JP2014505143A - Foaming thermoplastic reactor blends and foamed products made therefrom - Google Patents

Abstract

The invention comprises (a) a first propylene polymer component comprising 90-100% by weight propylene and 0-10% by weight comonomer, having a Tm of 120 ° C. or higher; (b) 30-90% by weight And a second propylene polymer component having a Mw of 30,000 g / mol or more and having a crystallinity different from the first polymer by at least 5%. An effervescent blend comprising a reactor polymer blend, before the polymer blend is combined with the blowing agent (i) a Tm of at least 120 ° C .; (ii) an MFR of 10 dg / min or higher; (iii) a tensile strength of at least 8 MPa; (iv) at least 200% of the elongation at break; and (v) the extensional viscosity of the strain rate and 180 ° C. for 1 sec ^-1 When measured in degrees, has a ratio linear viscosity of 5 or more elongation at break viscosity, the blend is foamed foaming agent, the foaming product has a density of 800 kg / m ³ or less, about effervescent blend .
[Selection figure] None

Description

This application claims the priority and benefit of USSN 12 / 986,645, filed January 7, 2011.
The present invention relates to a foamed product comprising an in-reactor polymer blend comprising two propylene-containing polymers having different degrees of crystallinity.

Foamed polymer materials are well known and are typically produced by introducing a physical blowing agent into the molten polymer stream, mixing the blowing agent and polymer, and extruding this mixture to atmosphere while shaping the mixture. Exposure to atmospheric conditions usually causes gasification of the blowing agent, thereby forming bubbles in the polymer. Under some conditions, the bubbles can remain isolated, producing a closed cell foam material. Under other conditions, usually more severe foaming conditions, the bubbles can rupture or interconnect, resulting in an open cell material. As an alternative to physical blowing agents, chemical blowing agents can be used, where chemical blowing agents undergo chemical degradation (usually by application of heat or pressure) within the polymer material, which causes gas formation.
The polymer melt must maintain high tensile stress (or melt strength) without breaking the cell interface. The breakage of the bubble interface leads to adjacent bubble coalescence, and repeated breakage leads to the formation of very large bubbles and the collapse of the foam. Once the foam is formed, its placement must remain stable while the thermoplastic cools and solidifies. Polyolefins such as low density polyethylene (LDPE) and polypropylene (PP) are commonly used for many non-crosslinked foam applications. For example, US Pat. No. 6,583,193 discloses an extruded and fused polypropylene foam, which is suitable for open cell or insulating applications that are useful for soundproofing applications. One of the useful and closed-cell types. Among these, polyethylene is preferred because it is easy to control foaming. Foams containing a polypropylene component are known, but in most cases such foams contain a significant proportion of additives that add controllability to the foaming process.

Polypropylene (PP) is relatively new for foam applications. Conventional PP is a semi-crystalline material having a linear molecular structure. Due to the lack of melt strength and elongational rheological properties, its use is limited to foams having a density higher than 500 kg / m ³ . This type of PP is not capable of controlling bubble growth or preventing bubble wall destruction during the foaming process.
In order to overcome low tensile strength without sacrificing processability, blends of polyolefins with components of high molecular weight (or low melt flow rate) materials are commonly used. Polyolefin foams made of polyolefins with ultra high molecular weight, ie, weight average molecular weights of about 4 × 10 ^{5 to} 6 × 10 ⁶ g / mol or more are disclosed in US Pat. No. 5,180,751. US '751 describes a polypropylene foam made of a polypropylene resin having a z-average molecular weight greater than 1 x 10 ⁶ and a Mz / Mw ratio greater than 3.0. US '571 also states that resins that yield acceptable foam sheets exhibit a bimodal molecular weight distribution, whereas unacceptable foam sheets exhibit a unimodal molecular weight distribution.

  PP is also a softer component, such as ethylene and vinyl acetate (EVA) copolymers, ethylene-ethyl acrylate copolymers (EEA), ethylene-acrylic acid copolymers (EAA), or other ethylene copolymers having a low melting point, etc. Can be made into soft foams for various applications. For example, US Pat. No. 6,590,006 discloses large cells comprising blends of high melt strength polypropylene and ethylene copolymers such as EVA, EEA, and EAA for use in sound absorption and thermal insulation applications. Disclosed is a foam.

U.S. Pat. No. 4,832,770 contains 80 to 20 wt% crystalline polypropylene-ethylene block copolymer containing no more than 20 wt% ethylene and having a melt index of no more than 2 and no more than 5 wt% Expanded polypropylene resin from a mixture of 20 to 80% by weight of crystalline polypropylene-ethylene block or random copolymer containing ethylene and having a melt index of 6 to 20, or a polypropylene homopolymer having a melt index of 6 to 20 Describes the manufacturing method.
In addition to the above, foam profiles of rubber, such as ethylene-propylene-diene (EPDM) rubber, have been used in vulcanized form for high mechanical strength. Due to the elastomeric properties of the EPDM rubber foam, the compressed foam adapts to the required shape when closed so that the intrusion of noise, dust and moisture is blocked, and is effective on the gaps and corners of automobile openings Compression becomes possible. However, the construction of EPDM rubber foam profiles and vulcanization of EPDM requires careful and difficult handling.

  A thermoplastic vulcanizate (TPV) composition is a thermoplastic material with a pre-crosslinked rubber phase, such as EPDM rubber, and much more easily into complex shapes, as is the case with thermoplastic molding. It can be formed and retains mechanical strength much longer while still being resistant to moisture and noise, dirt, and other uptake. However, known TPV foam compositions tend not to achieve the level of moisture uptake prevention that the equivalents of EPDM rubber foam compounds possess.

US Pat. No. 6,713,520 includes from about 15 to about 95 weight percent rubber, and from about 5 to about 85 weight percent thermoplastic component, based on the combined total weight of the rubber component and the thermoplastic component. A thermoplastic vulcanizate foam composition comprising a mixture, wherein the thermoplastic component is about 65 to about 90 weight percent of a conventional thermoplastic resin, and about 10 to about 10 weight percent based on the total weight of the thermoplastic component. A thermoplastic vulcanized foam composition comprising about 35 weight percent random propylene copolymer is described.
International Application No. 2004/016679 describes a flexible thermoplastic vulcanizate foam comprising a polyolefin thermoplastic resin, an at least partially crosslinked olefin elastomer, a hydrogenated styrenic block copolymer, and optional additives. Describes the body. Soft foam has a smooth surface, low water absorption, improved compression set and compressive load deflection.
These compositions exhibit better softness compared to isotactic polypropylene alone, but still lack other physical attributes. Physical blends also have poor miscibility problems. The immiscible components can be phase separated or allow migration of smaller components to the surface. Reactor blends, also called intimate blends (compositions containing two or more polymers made in the same reactor or series of reactors) are also often used to address these issues. However, finding catalyst systems that operate in the same environment to produce different polymers has been an important challenge.

  There is a strong and growing need in the market for polypropylene-based foams that have been traditionally supplied by materials such as polyurethane, polystyrene and polyethylene. Polypropylene-based foam provides additional benefits to this market area, such as high heat resistance, excellent chemical resistance, and insulation properties. There is an ongoing need for polypropylene with good processability and high elongational rheological properties that are desirable for foam applications.

  Furthermore, it has been found that a relatively simple method of preparing a polypropylene base material for foam applications having desirable properties, particularly the use of crosslinkers, such as post-polymerization treatment, or the formation of undesirable gels. There is a need for a process that does not require the use of selected comonomers, such as certain types of diene comonomers. In accordance with the present invention, a foamed product is provided that includes a reactor polymer blend that exhibits a unique combination of high melt flow rate combined with high tensile strength and elongation at break.

The present invention
(A) a first propylene polymer comprising 90-00 wt% propylene and 0 or more and less than 10 wt% comonomer and having a Tm of 120 ° C or higher (preferably 135 ° C or higher);
(B) 30-90% by weight propylene and 70-10% by weight comonomer, having a Mw of 30,000 g / mol or more and having a crystallinity different from the first polymer (eg at least relative to each other) A second propylene polymer component having 5%);
(C) A foamable thermoplastic in-reactor blend comprising 0-10% by weight of blowing agent relative to the total material in the blend, prior to being combined with the blowing agent,
(A) a Tm of at least 120 ° C (preferably at least 135 ° C);
(B) a melt flow rate of 10 dg / min or more;
(C) a tensile strength of at least 8 MPa;
(D) an elongation at break of at least 200%;
(E) having a ratio of elongational viscosity at break (measured at 180 ° C.) to linear viscosity of 5 or higher at a strain rate of 1 s ⁻¹ and when foamed using a foaming agent, the foamed product becomes (f ) Relates to a foamable thermoplastic in-reactor blend having a density of 800 kg / m ³ or less, preferably 400 kg / m ³ or less. Foam density is determined according to ASTM D1622-08.

The present invention also provides
(A) a first propylene polymer component comprising 90-100% by weight propylene and 0 to less than 10% by weight comonomer and having a Tm of 120 ° C. or higher;
(B) a crystallinity comprising 30-90% by weight propylene and 70-10% by weight comonomer, having a Mw of 30,000 g / mol or more and different from the first propylene polymer (eg at least relative to each other) A foamable thermoplastic in-reactor blend comprising a second propylene polymer component having a 5%)
(I) a Tm of at least 120 ° C;
(Ii) a melt flow rate of 10 dg / min or more;
(Iii) a tensile strength of at least 8 MPa;
(Iv) an elongation at break of at least 200%;
(V) has a ratio of the elongation at break (measured at 180 ° C.) to linear viscosity of 5 or higher at a strain rate of 1 s ⁻¹ and when foamed using a foaming agent, the foamed product (vi It also relates to a foamable thermoplastic in-reactor blend having a density of 800 kg / m ³ or less, preferably 400 kg / m ³ or less.

The present invention also provides
(A) a method of mixing a foaming agent with molten polyolefin to form a foamable mixture;
(B) a method of forming the foamable mixture (eg, extrusion or molding) such that the foaming agent expands within the mixture to form a foam;
(C) a method for obtaining a foamed product having a density of 800 kg / m ³ or less,
A method for producing a foamed polyolefin product, comprising:
(A) a first propylene polymer component comprising 90-100% by weight propylene and 0 to less than 10% by weight comonomer and having a Tm of 120 ° C. or higher;
(B) comprising 30 to 90 wt% propylene and 70 to 10 wt% comonomer, having a Mw of 30,000 g / mol or more and having a crystallinity different from the first polymer by at least 5%, A propylene polymer component comprising a foamable thermoplastic in-reactor polymer blend, wherein the polymer blend comprises:
(A) a Tm of at least 120 ° C .;
(B) a melt flow rate of 10 dg / min or more;
(C) a tensile strength of at least 8 MPa;
(D) an elongation at break of at least 200%; and (e) a method having a ratio of the elongation at break to linear viscosity of 5 or greater when the extensional viscosity is measured at a strain rate of 1 s ⁻¹ and 180 ° C. Also related.

Four different Henky strain rates (1, 5, 10, and 20 sec ⁻¹ ) at 180 ° C. for the products produced in Examples 1, 2, and 4 and for the comparative polymer PP1 Temporary extensional viscosity measured in For Examples 1, 2, and 4 and Comparative Example PP1, the cell structure of the injection foam portion at two different locations away from the injection port (35 and 90 mm) is shown.

  As used herein, the term “in-reactor polymer blend” does not require post-polymerization blending (although post-polymerization to incorporate, for example, modifiers, additives, or additional blend components into the resulting copolymer). Means a mixture of polymers produced in several polymerization stages. Each polymer component in the mixture has a unique molecular structure, such as comonomer content, composition distribution, molecular weight, molecular weight distribution, and / or molecular structure, such as a branched block copolymer. The various polymerization stages would normally be performed in different polymerization zones, i.e. in different reactors or in different parts of the same reactor, but these stages could be performed sequentially in the same polymerization zone. The polymer mixture is preferably produced in the same process or polymerization apparatus.

  The polymerization zone is defined as the region where the activated catalyst and monomer come into contact and the polymerization reaction takes place. If multiple reactors are used in either a series or parallel configuration, each reactor is considered a separate polymerization zone. For multi-stage polymerizations in both batch and continuous reactors, each polymerization stage is considered a separate polymerization zone.

  For the purposes of the present invention, a “semi-crystalline polymer” is defined as an olefin polymer having a crystallinity greater than 5%, and an “amorphous” or “semi-amorphous polymer” is a crystallinity of 5% or less. Is defined as an olefin polymer having The degree of crystallinity (percentage) is calculated using the heat of fusion obtained from the DSC as described in the experimental section below. Olefin polymer is defined to mean a polymer containing carbon and hydrogen but no heteroatoms. The copolymer has two or more different monomers. “Different” means monomers having different carbon numbers in ethylene-propylene copolymers, for example, or isomeric forms such as isobutene and 1-butene. The homopolymer has one monomer type, such as homopolypropylene.

  Blowing agents are chemicals (such as compounds or elements), and when in fluid form (usually gas), bubbles are present in polymeric materials such as plastics, elastomers, thermoplastics, plastomers, especially blends of the present invention. Used to form a structure. The blowing agent can form a cellular structure that is open, closed, or a combination thereof. The blowing agent is a solid that combines with the polymer blend and then later, usually induced by heat, light, radiation, or pressure, to expand the polymer material and form a fluid (usually a gas) that forms a cellular structure. Or it may be liquid. The foaming agent usually contains a polymeric material at least twice the original volume prior to addition of the foaming agent and foaming, preferably at least 3 times the original volume, preferably at least 5 times the original volume, preferably the original volume. Expand to at least 10 times the volume, preferably at least 50 times the original volume, preferably at least 100 times the original volume, preferably 1000 times the original volume.

Room temperature is 23 ° C. unless otherwise specified. The unit “1 / second”, also referred to as “second- ¹ ”, is the second power of seconds.

  As used herein, the term “branched block copolymer” means that a first polymer chain (also referred to as a macromonomer) having a reactive polymerizable chain end (eg, a reactive end) is second. Crosslink formation obtained when forming a structure containing a backbone defined by one of the polymer chains having branches of other polymer chains extending from the backbone by being incorporated into the polymer chain during the latter polymerization It is defined as a thing. The scaffolds and branches retain different and unique molecular structures such as chemical components and / or crystallinity. For example, a polypropylene homopolymer having vinyl chain ends can be incorporated into a propylene copolymer chain to form a branched cross-linked product having a propylene copolymer backbone and polypropylene side branches. Because the molecular structure / composition within the backbone and branches is different, the branched block composition usually has features from both the backbone and the branch. Branched block products are also referred to as branched cross-linked products. In one embodiment, the branch is composed of homopolypropylene and the backbone is selected from ethylene or C4-C12 alpha olefins, preferably ethylene, butene, pentene, hexene, heptene, octene, nonene, decene, undecene, and dodecene. Made of a propylene copolymer having at least one monomer. In another embodiment, both the backbone and the branch of the branched block polymer are composed of propylene copolymers, and the difference in crystallinity of the copolymers in the backbone and branches is at least 5% relative to each other, preferably Is at least 10%, more preferably at least 20%.

  In order to effectively incorporate a reactive polymer chain into the growing chain of another polymer, a first polymerization step that produces a macromonomer having a reactive end, such as a vinyl end group, is preferred. A macromonomer having a reactive end has 12 or more carbon atoms (preferably 20 or more, more preferably 30 or more, more preferably between 12 and 8000 carbon atoms) and increases. By vinyl, vinylidene, vinylene or other terminal group polymer that can be polymerized into a polymer chain. Vinyl end chains are generally more reactive than terminal vinylene chains or terminal vinylidene chains. Generally, the first polymerization step has a first vinyl end unsaturation of at least 50%, such as at least 60%, such as at least 70%, and even at least 80%, relative to the total unsaturated olefin chain ends. It is desirable to produce a polymer. Unsaturated chain ends are defined by protons as described in USSN 12 / 143,663, filed Jun. 20, 2008, particularly page 33 line 25 to page 34 line 11. Determine using NMR (collected at 120 ° C., 400 MHz).

  A “propylene polymer”, also referred to as a “propylene-containing polymer”, is a polymer having at least 40% by weight propylene monomer with the remainder being hydrocarbon monomers, preferably ethylene and / or C4-C12 hydrocarbon monomers, preferably ethylene and And / or supplemented with C4-C12 alpha olefins.

  As used herein, the term “heterogeneous blend” means a composition having two or more morphological phases in the same state. For example, a blend of two polymers that form separate packets (or finely divided phase regions) in which one polymer is dispersed within another polymer matrix is said to be inhomogeneous within the solid. Heterogeneous blends are also defined to include co-continuous blends where the blend components appear to the eye but are unclear which is the continuous phase and which is the discontinuous phase. . Such morphology is determined using scanning electron microscopy (SEM) or atomic force microscopy (AFM). If the SEM and AFM provide different data, use the AFM data. By continuous phase is meant a matrix phase within a heterogeneous blend. By discontinuous phase is meant a dispersed phase within a heterogeneous blend. The finely divided phase regions are also called particles.

  In contrast, a “homogeneous blend” is a composition having substantially one morphological phase in the same state. For example, a blend of two polymers in which one polymer is miscible with another polymer is said to be homogeneous in the solid. Such a form is determined using AFM. Miscible means that a blend of two or more polymers exhibits a single phase behavior with respect to the glass transition temperature, eg, Tg is tan δ (ie loss loss elasticity) of a dynamic thermal analyzer (DMTA). The ratio of the modulus to the storage modulus) and the temperature on the trace, which means that it exists as a single, sharp transition temperature. In contrast, for immiscible blends, two separate transition temperatures are observed, which usually corresponds to the temperature for each of the individual components of the blend. The polymer blend is therefore miscible when there is one Tg shown on the DMTA trace. Immiscible blends are heterogeneous, whereas miscible blends are homogeneous.

Polymer blend In another aspect, the invention provides:
(A) 90-100 wt% propylene, 0-10 wt% comonomer (preferably selected from ethylene and C4-C12 olefins), and 120 ° C or higher (preferably 130 ° C or higher, preferably 135 ° C or higher, A first propylene-containing polymer component having a Tm of preferably 140 ° C. or higher, preferably 150 ° C. or higher,
(B) 30-90% by weight propylene, 10-70% by weight comonomer (preferably selected from ethylene and C4-C12 olefins), and Mw of 30,000 g / mol or more (preferably 50,000 g / mol) Or more, preferably 75,000 g / mol or more) and a foamable thermoplastic inreactor comprising a second propylene-containing polymer component having a different degree of crystallinity than the first polymer (preferably having a different Tg). A blend,
(I) 120 ° C or higher (preferably 130 ° C or higher, preferably 135 ° C or higher, preferably 140 ° C or higher, preferably 150 ° C or higher) as determined by DSC as described in the experimental section below. Tm;
(Ii) A melt flow rate of 10 dg / min or more (preferably 20 dg / min or more, preferably 30 dg / min or more, preferably 40 dg / min or more) as determined by ASTM 1238 at 230 ° C. and 2.16 kg;
(Iii) ASTM D1708, as determined by 23 ° C., a fracture tensile strength of at least 8 MPa (preferably at least 10 MPa, preferably at least 12 MPa, preferably at least 15 MPa);
(Iv) Elongation at break of at least 200% (preferably 300% or more, preferably 400% or more, preferably 500% or more) as determined by ASTM D1708;
(V) When the extensional viscosity is measured at 180 ° C., the ratio of the elongational viscosity at break at a strain rate of 1 sec ⁻¹ to the linear viscosity of 5 or more (preferably 8 or more, preferably 10 or more, preferably 15 or more. ),
(Vi) optionally having a branched block product having a peak between 44-45 ppm in the ¹³ C NMR spectrum, preferably foamed with a blowing agent, It relates to a foamable thermoplastic polymer blend having a density of m ³ or less, preferably 400 kg / m ³ or less, preferably 300 kg / cm ³ or less.

Different crystallinity means that the percent crystallinity differs from each other by at least 5%, preferably at least 10%, preferably at least 15%, preferably at least 20%, preferably at least 30%. The percent crystallinity is determined by DSC as described in the experimental section below. Different Tg means that the Tg differs from each other by at least 5%, preferably at least 10%, preferably at least 20%, preferably at least 30%. Tg is determined by DSC as described in the experimental section below.
Preferably, the reactor blend has a heat of fusion (Hf) of 80 J / g or less, more preferably 70 J / g or less. (Hf is determined by DSC as described in the experimental section below). In another embodiment, the reactor blend has a heat of fusion of 30 J / g or greater, preferably 40 J / g or greater. Instead, the reactor blend has a crystallinity of 50% or less, preferably 40% or less. In another embodiment, the reactor blend has a crystallinity of 15% or more, preferably 20% or more.
Preferably, the in-reactor polymer blend has a fracture tensile strength of 10 MPa or more (determined by ASTM D1708 at 23 ° C.), preferably 15 MPa or more, preferably 20 MPa or more.

  Useful blends described herein also exhibit strain hardening in tensile strength. After reaching the yield point, the blend has a period of strain hardening, during which the stress increases again to the final strength in the stress-strain curve measured according to ASTM D1708 with increasing strain. Strain hardening is measured by the ratio of stress at 300% strain (M300) to stress at 100% strain (M100). A ratio of M300 / M100 greater than 1 indicates strain hardening. Strain hardening can also be measured using the ratio of M100 to stress at 500% or 800% strain. M500 / M100 is defined as the ratio of stress at 500% strain to stress at 100% strain. Similarly, M800 / M100 is defined as the ratio of stress at 800% strain to stress at 100% strain.

  Preferred in-reactor polymer blends described herein have an M300 / M100 strain hardening ratio greater than 1.0, preferably greater than 1.02, preferably greater than 1.04; and / or Greater than, preferably greater than 1.03, preferably greater than 1.05, M500 / M100 strain hardening ratio; and / or greater than 1, preferably greater than 1.1, preferably greater than 1.2 M800 / M100 Has a strain hardening ratio. Instead, the in-reactor polymer blends described herein have a strain hardening ratio Mx / M100 (where Mx is the breaking tensile strength) greater than 1.2.

Useful blends described herein also have a toughness (as measured by ASTM D1708) of 50 megajoules / m ³ , preferably 60 megajoules / m ³ , preferably 80 megajoules / m ^3. Have. Toughness is defined as the ability of a polymer to absorb applied energy until failure. The area under the stress-strain curve is used as a measure of toughness at room temperature.

Generally, the in-reactor blend of the present invention has a 4000 Pa. s or less, preferably 3000 Pa.s. s or less, more preferably 2000 Pa. s or less, more preferably 1500 Pa. It has a complex viscosity of s or less. The complex viscosity is measured at 190 ° C. over an angular frequency range of 0.01 to 100 rad / s using the procedure described in the experimental section for dynamic shear melt rheology.
Most thermoplastic polyolefins exhibit pseudoplastic flow behavior and their viscosity decreases with increasing shear rate (also called shear thinning). This shear thinning behavior can be demonstrated by reducing the complex viscosity with increasing shear rate. The in-reactor polymer blend of the present invention has good shear thinning. One method for quantifying shear thinning uses the ratio of complex viscosity at a frequency of 0.01 rad / s to complex viscosity at a frequency of 100 rad / s. Preferably, when the complex viscosity is measured at 190 ° C., the complex viscosity ratio of the in-reactor polymer blend produced in the present invention is 20 or more, more preferably 50 or more, and even more preferably 100 or more.

  Shear thinning can also be characterized using the shear thinning index. The term “shear thinning index” is determined using a plot comparing the logarithm of the kinematic viscosity coefficient (base 10) and the logarithm of frequency (base 10). The gradient is the difference between the logarithm (dynamic viscosity coefficient) at a frequency of 100 rad / s and the logarithm (dynamic viscosity coefficient) at a frequency of 0.01 rad / s divided by four. These plots are typical outputs of a small amplitude oscillatory shear (SAOS) experiment. For propylene copolymers, the conventional SAOS test temperature is 190 ° C. The polymer viscosity is measured in poise (dyne seconds / square centimeter), at a shear rate in the range of 0-100 rad / s, using a dynamic viscoelasticity measuring device, such as an Advanced Rheometrics Expansion System (ARES), in a nitrogen atmosphere, It is convenient to measure at 190 ° C. In general, a low shear thinning index indicates that the polymer is extremely shear thinning and can be easily processed by high shear processing such as injection molding. As this slope becomes more negative, the kinematic viscosity coefficient decreases faster with increasing frequency. Preferably, the in-reactor polymer blend produced herein has a shear thinning index of less than -0.2. These types of polymer blends are easily processed by high shear rate manufacturing methods such as injection molding.

Useful blends described herein also have the property of strain hardening at extensional viscosity. An important feature that can be obtained from an extensional viscosity measurement is the nature of strain hardening in the molten state. Strain hardening is observed as a sudden, rapid increase in extensional viscosity in a plot of temporary extensional viscosity versus time. This steep rise away from the behavior of linear viscoelastic materials was reported to LDPE in the 1960s (reference: J. Meissner, Rheol. Acta., Vol. 8, 78, 1969). Due to the presence of long branches. Strain hardening ratio is defined as the ratio of elongational viscosity at break at a given strain rate to linear viscosity. A ratio greater than 1 is defined as strain hardening. In one embodiment, the in-reactor polymer blend of the present invention has strain hardening with extensional viscosity. When the extensional viscosity is measured at a strain rate of 1 sec ^-1 and a temperature of 180 ° C, the strain hardening ratio is 2 or more, preferably 5 or more, more preferably 10 or more, and even more preferably 15 or more. Instead, when the extensional viscosity is measured at a strain rate of 5 seconds ^-1 and a temperature of 180 ° C, the strain hardening ratio is 2 or more, preferably 5 or more, more preferably 8 or more, and even more preferably 12 or more. .

  Preferably, the in-reactor polymer blend produced herein has a Shore hardness of 15A to 90D, such as 30A to 90D (measured with ISO 868).

The in-reactor polymer blends described herein have a unique combination of flowability and strong mechanical properties, such as elongation, strain hardening, tensile strength, etc., and a propylene-containing first polymer; A branched block copolymer having a propylene-containing second polymer that differs in crystallinity by at least 5%, usually at least 10%, from the first polymer, a backbone comprising the second polymer, and a branch comprising the first polymer. Including. Preferably, a more crystalline material is utilized as the first polymer and thus as the side branch of the branched block copolymer. Instead, a less crystalline material is utilized as the first polymer and thus as the side branch of the branched block copolymer, which is characterized as a more crystalline backbone. For purposes of the present invention, a branched block copolymer having a backbone containing a second polymer and a branch containing the first polymer was identified by ¹³ C NMR as described below in the Examples section. The
The first and second polymers for the in-reactor polymer blend may be selected from propylene homopolymer, semi-crystalline propylene copolymer and amorphous propylene polymer, such as a thermoplastic elastomer of propylene, respectively. Any of homopolymers, semi-crystalline propylene copolymers and amorphous propylene polymers (usually propylene elastomers) can be used as either the branch or backbone of the branched block composition.

In one embodiment, the first or second polymer component is a propylene homopolymer. Preferably, the polypropylene is isotactic, highly isotactic, or highly syndiotactic polypropylene. As used herein, “isotactic” has an isotactic pentad of at least 20% of methyl groups derived from propylene, preferably at least 40%, as analyzed by ¹³ C NMR. Defined as having an isotactic pentad. As used herein, “highly isotactic” means having a pentad of at least 60% isotactic, as analyzed by ¹³ C NMR (as described in the experimental section below). Is defined as The propylene homopolymer can be used as either the first or second polymer or as the side branch or backbone of the branched block copolymer, but as the first polymer, ie as the side branch of the branched block copolymer. Generally used.

Particularly useful propylene homopolymers have a crystallinity of at least 30%, generally at least 40%, as determined by differential scanning calorimetry (DSC), as described in the experimental section below. Useful propylene homopolymers are typically greater than 60 J / g, instead at least 70 J / g, instead at least 80 J / g, instead, as determined by DSC analysis, as described in the experimental section below. It has a heat of fusion of at least 90 J / g. Suitable propylene homopolymers usually have a melting temperature of at least 100 ° C, generally at least 130 ° C, preferably at least 135 ° C, preferably at least 140 ° C and even at least 150 ° C.
Useful propylene homopolymers usually have a weight average molecular weight of less than 200,000 g / mol, such as 150,000 g / mol or less, and 2 dg / min or more, conveniently 5 dg / min or more, conveniently 10 dg / min or more, especially It has an MFR of 20 dg / min or more.

  In another embodiment, the semi-crystalline propylene copolymer is utilized as either the first or second polymer in the polymer blend, and as either the backbone or side branch in the branched block structure. Propylene copolymers are generally made with polymerization catalysts that form a basic or substantially isotactic propylene sequence, but introduce steric and site errors in the incorporation of propylene in the copolymer. A steric error is one in which propylene is inserted into the chain with a stereoregularity that is not isotactic. Propylene molecules are usually added head-to-tail rather than tail-to-tail or head-to-head. Head-to-tail addition results in polypropylene chains with pendant methyl groups attached to alternating carbon. This alternating arrangement breaks when tail-to-tail or head-to-head addition occurs. Site errors are those in which propylene is inserted with a methylene group or methine group adjacent to a similar group in the propylene inserted immediately before. Such errors are more prevalent after introduction into a semi-crystalline propylene copolymer such as a comonomer such as ethylene or 1-hexene. While not wishing to be limited by this theory, the introduction of these errors into the propylene copolymer appears to be important in the use of these propylene copolymers as semi-crystalline propylene copolymers, especially in the presence of comonomers. It has been. Despite the presence of these errors, the semi-crystalline propylene copolymer is statistically random in the comonomer distribution.

  Semicrystalline propylene copolymers typically allow only the addition of a single statistical mode of propylene and comonomers in a well-mixed, continuous monomer feed that is stirred in a tank polymerization reactor and is a polymer of semicrystalline propylene copolymers Made with a single site metallocene catalyst that allows only a single polymerization environment for all of the chains.

In another embodiment, the semicrystalline propylene copolymer has a block structure.
Suitable semi-crystalline propylene copolymers are propylene and at least one comonomer selected from ethylene and C4 to C12 α-olefins such as 1-butene; 1-pentene; 1-hexene; 1-heptene; 1-octene; Formed by polymerizing nonene; 1-decene; 2-methyl-1-propene; 3-methyl-1-pentene; 4-methyl-1-pentene; 5-methyl-1-hexene; Is done. Other α-olefins such as 1-butene; 1-pentene; 2-methylpentene; 1,3-methyl-1-butene; 1-hexene; 3-methyl-1-pentene; 4-methyl-1-pentene; 3,3-dimethyl-1-butene; methyl-1-hexene; dimethyl-1-pentene; trimethyl-1-butene; ethyl-1-pentene; methyl-1-pentene; dimethyl-1-hexene; Pentene; Ethyl-1-hexene; Methylethyl-1-pentene; Diethyl-1-butene; Propyl-1-pentene; Methyl-1-nonene; 1-Nonene; Dimethyl-1-octene; Trimethyl-1-heptene; Copolymers of propylene having -1-octene; methylethyl-1-butene; diethyl-1-hexene; and 1-dodecene. It can be used. More preferred are propylene / ethylene and propylene / 1-hexene copolymers.

  Preferred semi-crystalline propylene copolymers have a peak melting temperature of 10 to 170 ° C., usually 30 to 150 ° C .; a weight average molecular weight such as 200,000 g / mol or less, such as 150,000 g / mol or less; 0 ° C. or more, usually 20 ° C. It has the above crystallization temperature. A moderate level (5-10%) of crystallinity is also desirable for applications where elastic properties are important. Preferred semicrystalline propylene copolymers have a crystallinity greater than 5%, preferably greater than 10%. Preferred semicrystalline propylene copolymers have a weight average molecular weight of 20,000 g / mol or more, such as 50,000 g / mol or more.

  In another embodiment, the first or second polymer is an amorphous polymer (eg, an amorphous thermoplastic elastomer). As used herein, an amorphous polymer is defined as an olefin polymer having a crystallinity of less than 5% as determined by DSC. In general, amorphous polymers are ethylene or C4-C12 alpha-olefins such as 1-butene; 1-heptene; 1-hexene; 1-octene; 1-decene; 2-methyl-1-propene; A propylene copolymer having at least one monomer selected from 1-pentene; 4-methyl-1-pentene; 5-methyl-1-hexene; and mixtures thereof. Copolymers of ethylene and propylene, or other alpha-olefins such as ethylene or propylene, for example 1-butene; 1-pentene; 2-methylpentene; 1,3-methyl-1-butene; 1-hexene; 3-methyl-1 4-methyl-1-pentene; 3,3-dimethyl-1-butene; methyl-1-hexene; dimethyl-1-pentene; trimethyl-1-butene; ethyl-1-pentene; Dimethyl-1-hexene; trimethyl-1-pentene; ethyl-1-hexene; methylethyl-1-pentene; diethyl-1-butene; propyl-1-pentene; methyl-1-nonene; 1-octene; trimethyl-1-heptene; ethyl-1-octene; methylethyl-1-butene; diethyl 1-hexene, copolymers and the like and 1-dodecene can also be used. Preferably, the amorphous copolymer is a propylene / ethylene copolymer.

  The amorphous nature of this component derives from the disruption of the isotactic propylene sequence, generally through the incorporation of comonomers and / or the presence of steric or site errors. The percentage of copolymerized alpha-olefin in the amorphous copolymer is generally in the range of 2-50 wt%, alternatively 5-30 wt%. One, two, three or more alpha-olefins can be copolymerized with propylene. In another embodiment, the amorphous polymer is a homopolymer, such as atactic polypropylene.

  Useful amorphous propylene polymers have a weight average molecular weight of 200,000 g / mol or less, such as 150,000 g / mol or less, such as 120,000 g / mol or less. Useful amorphous propylene polymers have a weight average molecular weight of 30,000 g / mol or higher, such as 50,000 g / mol or higher, such as 75,000 g / mol or higher.

Any combination of the first and second polymer components preferably forms a population of branched block compositions having a molecular structure relative to the backbone that is different from the molecular structure of the side branch.
Foamable and foamed compositions of the invention typically utilize a blowing agent to cause the polymer to increase due to foaming.
Particularly preferred blowing agents include both physical and chemical blowing agents. Chemical blowing agents are azodicarbonamide, azodiisobutyronitrile, benzenesulfone hydrazide, 4,4-oxybenzenesulfonyl semicarbazide, p-toluenesulfonyl semicarbazide, barium azodicarboxylate, N, N'-dimethyl-N, N'- Includes dinitrosotephthalamide and trihydrazinotriazine.

  Chemical blowing agents include aliphatic hydrocarbons having 1 to 9 carbon atoms, halogenated aliphatic hydrocarbons having 1 to 4 carbon atoms, and aliphatic alcohols having 1 to 3 carbon atoms. Contains organic blowing agent. Aliphatic hydrocarbons include methane, ethane, propane, n-butane, isobutane, n-pentane, isopentane, neopentane, and the like. The chemical blowing agent comprises a halogenated hydrocarbon, preferably a fluorinated hydrocarbon. Examples of fluorinated hydrocarbons are: methyl fluoride; perfluoromethane; ethyl fluoride; 1,1-difluoroethane (HFC-152a); 1,1,1-trifluoroethane (HFC-143a); 1,2-tetrafluoro-ethane (HFC-134a); pentafluoroethane; perfluoroethane; 2,2-difluoropropane; 1,1,1-trifluoropropane; perfluoropropane; perfluorobutane; and perfluoro Including cyclobutane. Partially halogenated chlorocarbons and chlorofluorocarbons for use in the present invention are methyl chloride; methylene chloride; ethyl chloride; 1,1,1-trichloroethane; 1,1-dichloro-1-fluoroethane ( HCFC-141b); 1-chloro-1,1-difluoroethane (HCFC-142b); 1,1-dichloro-2,2,2-trifluoroethane (HCFC-123); and 1-chloro-1,2, 2,2-tetrafluoroethane (HCFC-124) is included. Fully halogenated chlorofluorocarbons are trichloromonofluoromethane (CFC-11); dichlorodifluoromethane (CFC-12); trichlorotrifluoroethane (CFC-113); dichlorotetrafluoroethane (CFC-114); chloro Heptafluoropropane; and dichlorohexafluoropropane. Fully halogenated chlorofluorocarbons are not preferred. Aliphatic alcohols useful as blowing agents include methanol, ethanol, n-propanol, and isopropanol.

Suitable inorganic blowing agents useful for making the foams of the present invention include carbon dioxide, nitrogen, argon, water, air, nitrogen, and helium. Inorganic blowing agents also include sodium bicarbonate; sodium carbonate; ammonium bicarbonate; ammonium carbonate; ammonium nitrite; nitroso compounds such as N, N'-dimethyl-N, N'-dinitrosotephthalamide and N, N'-di. Nitrosopentamethylenetetramine; azo compounds such as azodicarbonamide, azobisisobutyronitrile, azocyclohexylnitrile, azodiaminobenzene, and barium azodicarboxylate; sulfonyl hydrazide compounds such as benzenesulfonyl hydrazide, toluenesulfonyl hydrazide, p, p '-Oxybis (benzenesulfonylhydrazide), and diphenylsulfone-3,3'-disulfonylhydrazide; and azide compounds such as calcium azide, 4,4'-diphenyldisulfonide Azide, and p- including toluenesulfonyl azide.
The amount of blowing agent to make a foam-forming polymer composition (usually a gel) by incorporation into the polymer composition (usually a polymer melt) is preferably about 0. 0 to the total material in the blend. 01 to about 10% by weight, most preferably about 0.1 to 5% by weight. The level of blowing agent is often varied to obtain the desired foam density.

  Foaming aids can be used with foaming agents. Simultaneous use of the foaming agent with the foaming aid contributes to lowering the decomposition temperature of the foaming agent, accelerating the decomposition, and homogenizing the bubbles. Examples of foaming aids can include organic acids such as salicylic acid, phthalic acid, stearic acid and nitric acid, urea and derivatives thereof. The amount of foaming aid incorporated into the polymer composition (usually the polymer melt) is preferably from about 0.01 to about 10% by weight, most preferably from about 0.1 to about 10% by weight of the total material in the blend. 5% by weight, preferably 0.5 to 3% by weight.

  In a preferred embodiment, the reactor blend of the present invention comprises (i) 90-100% by weight (preferably 92-99% by weight, preferably 95-97% by weight) propylene and 0 to less than 10% by weight (alternately 1 -8 wt%, alternating 3-5 wt% comonomer (preferably ethylene, butene, hexene or octene), with a melting point of 120 ° C or higher (preferably 130 ° C or higher, preferably 135 ° C or higher, preferably 140 And (ii) 30 to 90 wt% (preferably 35 to 85 wt%, preferably 40 to 80 wt%) of propylene and 70 to 10 wt. % By weight (preferably 65-15% by weight, preferably 60-20% by weight) of comonomer (preferably ethylene, butene, hex And a second propylene polymer having a Mw of 30,000 g / mol or more, preferably 50,000 g / mol or more, preferably 75,000 g / mol or more; (iii) 0.01- 10% by weight (based on the weight of the reactor blend).

In a preferred embodiment, the first propylene polymer is a propylene homopolymer or random copolymer (eg, up to 5% by weight comonomer) having a melting point of 140 ° C. or higher, and the second propylene polymer is an amorphous copolymer of propylene 10 to 30% by weight of ethylene, butene, hexene or octene, having a mm triad regularity index of 50% or less, preferably 40% or less, preferably 30% or less, preferably 20% or less. The mm triad regularity is determined from the ¹³ C NMR spectrum of the polymer as described below and as described in US Pat. No. 5,504,172. Preferred amorphous copolymers used in embodiments of the present invention may also have a propylene stereoregularity index (m / r) ranging from an upper limit of 1 to a lower limit of about 0.6, 0.4, or 0.3. it can. The propylene stereoregularity index, expressed herein as “m / r”, is determined by ¹³ C NMR. The propylene stereoregularity index m / r is calculated as defined in HN Cheng, Macromolecules, 17, 1950 (1984) and as described in US Pat. No. 5,504,172. The symbolic designation “m” or “r” describes the configuration of a pair of adjacent propylene groups, “m” refers to meso and “r” refers to racemic.

  The ratio of the first polymer component to the second polymer component in the reactor blend depends on the needs of the end use application. The thermal properties of the final in-reactor polymer blend depend on the properties of each component in the blend and the ratio of each component. In general, in-reactor blends have a crystallinity of 80% or less, usually 50% or less when calculated using the heat of fusion obtained from DSC analysis. If there are multiple melting peaks during a heating cycle, use the sum of heat of fusion from all melting peaks. The heat of fusion for 100% crystallinity is selected from the homopolymer of the main composition in the in-reactor polymer blend. For example, if the polymer blend is made of a propylene homopolymer and a propylene / ethylene copolymer, propylene is the primary composition and the heat of fusion of 100% crystallinity polypropylene is used (eg, 189 J / g). In one embodiment, the polymer blend produced in the in-reactor has a heat of fusion of between about 10 and about 70 J / g, such as between about 10 and about 60 J / g, such as between about 20 and about 50 J / g. Have.

  In-reactor blends usually have a melting temperature of 120 ° C. or higher, generally 130 ° C. or higher, such as 135 ° C. or higher, such as 140 ° C. or higher, such as 150 ° C. or higher. As used herein for in-reactor polymer blends, the term “melting point” is the highest temperature peak of the first and second melting peaks determined by DSC. In one embodiment of the invention, the polymer has a single melting peak. Typically, a sample of the in-reactor polymer blend will exhibit a second melting peak adjacent to the first peak, and these peaks together are considered a single melting peak. The highest peak temperature of these peaks is considered the melting point. The in-reactor polymer blend preferably has a DSC melting point ranging from an upper limit of 170 ° C, 160 ° C, 140 ° C, 120 ° C, or 90 ° C to a lower limit of 20 ° C, 30 ° C, 40 ° C, or 50 ° C. Have.

  In general, in-reactor blends have a crystallization temperature of 130 ° C. or less. As used herein, the term “peak crystallization temperature” for an in-reactor polymer blend is the highest temperature peak of the first and second crystallization peaks as determined by DSC. In one embodiment of the invention, the polymer has a single crystal peak. If the crystallinity of the first and second polymer components in the in-reactor blend is close, the polymer blend will show a second crystallisation peak adjacent to the first peak, and these peaks together It is regarded as a single crystal peak. The highest peak temperature among these peaks is regarded as the peak crystallization temperature. If the crystallinity of the first and second polymer components in the in-reactor blend is far apart, the polymer blend will show two individual peaks for each component. The in-reactor polymer blend preferably has a DSC ranging from an upper limit of 120 ° C, 100 ° C, 90 ° C, 70 ° C, or 40 ° C to a lower limit of 0 ° C, 10 ° C, 30 ° C, 40 ° C, or 70 ° C. With a crystallization temperature.

  It is believed that the melting temperature of the resulting polymer blend directly reflects the degree of crystallinity of the crystalline polymer component in the blend. The polymer blend can have a high melting temperature over a wide range of heats of fusion. In one embodiment, the polymer produced has a melting temperature of 135 ° C. or higher and a heat of fusion of 70 J / g or lower, preferably 145 ° C. or higher and 60 J / g or lower, more preferably 150 ° C. or higher and 50 J / g. It has the following heat of fusion. A lower value of heat of fusion means a softer material. Instead, the polymer blends of the present invention have a Shore hardness of 30A-40D and a melting temperature of 145 ° C or higher.

  The in-reactor blend has a weight of average molecular weight between 20,000 and 200,000 g / mol, such as between 30,000 and 150,000 g / mol, and the polydispersity index (PDI = Mw / Mn) is It is convenient to be in the range of 1.5-40. The polydispersity index is determined in part by the catalyst and process conditions utilized in the polymerization process. For example, polymerization involving multiple catalysts can produce copolymers having a broader or multimodal molecular weight distribution. Multiple reactors with different polymerization conditions can produce polymer blends with a multimodal molecular weight distribution. In one embodiment, the resulting polymer blend can have a unimodal, bimodal or multimodal Mw / Mn. Bimodal or multimodal means that a size exclusion chromatography (SEC) trace has multiple peaks or inflection points. An inflection point is a point at which the sign of the second derivative of the curve changes (eg, from negative to positive or vice versa).

  The molecular weight of each component in the in-reactor blend can be optimized for a particular application. In general, the molecular weight of the crystalline component should exceed the length of the entangled molecule, but the molecular weight of the less crystalline or amorphous component is such that the crystalline component becomes a physical network within the solid, and the polymer segment. It should be long enough to be able to be joined together. If the molecular weight of the first polymer is low, the second polymer should achieve good mechanical strength by having a higher molecular weight.

  The amount of the first polymer relative to the second polymer component can vary widely depending on the nature of the component polymer and the intended end use of the polymer blend. In particular, however, one advantage of the process of the present invention is that it produces a polymer blend that comprises a lower crystalline propylene copolymer of greater than 20%, such as greater than 50%, such as greater than 70%, of the total in-reactor polymer blend. Ability that can.

  To determine the properties of the component polymers, the polymer blend can be separated into fractions by solvent extraction (also called fractionation). Typical solvents are saturated hydrocarbons such as hexane, cyclohexane, heptane or xylene. The extraction temperature can range from room temperature to the boiling point of the solvent. The polymers become more soluble when they are compressed into thin films and then cut into small pieces. They can also be comminuted into granules or powders before being dissolved. For polymer blends containing homopolypropylene, the polypropylene component can be separated using cyclohexane refluxed for 24 hours. The insoluble fraction includes polypropylene and a portion of the branched block product. For in-reactor blends containing an amorphous component, the amorphous component can be isolated by contacting the blend with cyclohexane at 25 ° C. for 48 hours. The soluble fraction contains an amorphous component. Alternatively, several fractions can be obtained by fractional solvent fractionation of in-reactor blends with several solvents having increasing solubilities and boiling points. In a thick glass bottle with a screw cap seal, nominally about 10 grams of in-reactor blend was contacted with about 500 ml of cyclohexane. The sealed bottle is maintained at 25 ° C. for 48 hours. At the end of this period, the solution is decanted / filtered and evaporated to yield a polymer residue soluble in cyclohexane at 25 ° C. To the insoluble residue, add enough cyclohexane to bring the volume to about 500 ml and then maintain the bottle at 30 ° C. for 48 hours. Decanting / filtering the soluble polymer and evaporating yields a polymer residue that is soluble in cyclohexane at 30 ° C. Thus, a fraction of the in-reactor blend that is soluble at temperatures between 40 ° C. and 60 ° C. is obtained at temperatures that increase by about 5 ° C. per stage. An increase in temperature above 100 ° C. can be accommodated when xylene is used as the solvent instead of cyclohexane. The temperature and temperature interval can be varied according to the distribution of the in-reactor blend.

  The in-reactor blend conveniently has cyclohexane refluxing an insoluble fraction of 70% by weight or less, preferably 60% by weight or less. Instead, the in-reactor blend has a fraction that is soluble at room temperature of cyclohexane at 20% or more, preferably 30% or more, more preferably 40% or more by weight.

  In one embodiment, the in-reactor polymer blend of the present invention is between 60-115 ° C. when fractionated using crystal analysis fractionation (CRYSTAF) using the procedure described in the experimental section. It has a fraction that elutes and a soluble fraction that elutes below 5 ° C. The fraction corresponding to the highest temperature peak is called the highly crystalline fraction. The soluble fraction is therefore called the amorphous elastomer component. Depending on the crystallinity of the first and second polymers and the branched block composition, the peak temperature may shift, or additional peaks may exist. Instead, if a semi-crystalline propylene copolymer is present in the blend, the fraction elutes at a temperature between 0-80 ° C.

The presence of a branched block structure can be detected using nuclear magnetic resonance spectroscopy (NMR). ^{In 13} C NMR, the polymer is dissolved in tetrachloroethane-d 2 at 140 ° C. and the spectrum is collected at 125 ° C. A peak corresponding to methylene adjacent to the branch point is found between 44 and 45 ppm. The arrangement of iPP chains relative to long chain branches is discussed by Weng, Hu, Dekmezian, and Ruff (Macromolecules 2002, 35, 3838-3843). For propylene branches between propylene in the backbone, methylene is found at 44.88, 44.74, and 44.08 ppm. Branched methine is found at 31.84 ppm. For in-reactor polymer blends having a low content branched block composition, the blend should first be fractionated into components. The signal for the branched block component is found in the same fraction as the homopolypropylene component. Preferred in-reactor polymer blends are 0.01 (determined by ¹³ C NMR) per 1000 or more carbon atoms, preferably 0.03 or more, preferably 0.05 or more, alternating 1000 carbon atoms. 0.01 to 2 branches per unit.
The branched block structure can be observed in a micro-amplitude oscillatory shear (SAOS) test of the molten polymer performed on a dynamic (vibration) rheometer. From the data generated in such a test, the phase or loss angle δ can be determined, which is the inverse tangent of the ratio of G ″ (loss modulus) to G ′ (storage modulus). For typical linear polymers, the chain relaxes in the melt, adsorbs energy, and allows the loss modulus to be much greater than the storage modulus, so at low frequencies (or long periods) Loss angle approaches 90 °. As the frequency increases, more chains relax so slowly that they cannot absorb energy during vibration and the storage modulus increases compared to the loss modulus. Eventually, the storage modulus and loss modulus are equal and the loss angle reaches 45 °. In contrast, a branched polymer stretches very slowly because the branch needs to shrink before the chain backbone can relax along its tube in the melt. The polymer never reaches a state where all its chains can relax during vibration, and the loss angle never reaches 90 ° even at the lowest frequency ω of the experiment. The loss angle is also relatively independent of the frequency of vibration of the SAOS experiment, which is another indication that the chain cannot relax on these time scales.

  In the plot of phase angle δ versus measured frequency ω, polymers with long chain branches show a horizontal range in the function of δ (ω), whereas linear polymers have such a horizontal range. Not done. According to Garcia-Franco et al. (Macromolecules 2001, 34, No. 10, 3115-3117), as the amount of long chain branching that occurs in the polymer sample increases, the horizontal area of the above plot shows a lower phase angle. will shift to δ. The critical relaxation index n is obtained by dividing the phase angle at which the horizontal region occurs by the phase angle 90 °. This n can then be used to calculate the gel stiffness using the following formula:

(Where η ^* represents complex viscosity (Pa.s), ω represents frequency, S is gel stiffness, and Γ is a gamma function (Beyer, WH Ed., CRC Handbook of Mathematical Sciences 5 ^th Ed., CRC Press, Boca Rotan, 1978), where n is the critical relaxation index). The polymer produced herein is preferably 150 Pa.s. s, preferably at least 300 Pa.s. s, more preferably at least 500 Pa.s. s gel stiffness. Gel stiffness is determined by a test temperature of 190 ° C. The preferred critical relaxation index n for the polymers produced herein is less than 1 and above 0, generally n is between 0.1 and 0.92, preferably 0.2 and 0. .85.

It has been found that resins with relatively high melt elasticity expand more easily into good quality foams with high levels of open cells. The elasticity of the polymer melt compared to its viscosity can be expressed as tan δ, where tan δ is the storage modulus (G ′ as measured by SAOS) of the loss modulus (G ″ as measured by SAOS). )). Since it is desirable to have a resin whose melt elasticity is relatively greater than its viscosity, an in-reactor blend having a relatively small tan δ is preferred. In a preferred embodiment, the in-reactor blend produced herein has a tan δ measured at an angular frequency of 100 rad / s and a G ′ and G ″ measured at 190 ° C. of 2.0 or less, Preferably it has a tan δ of 1.5 or less, more preferably 1.2 or less.
Small amplitude oscillatory shear (SAOS) data, pages 273-275 in RB Bird, RC Armstrong, and O. Hassager, Dynamics of Polymeric Liquids, Volume 1, Fluid Mechanics, 2 nd Edition, John Wiley and Sons, the (1987) The procedure can be used to convert to a separate relaxation vector. Storage modulus and loss modulus are functions simultaneously:

And a least squares fit with relaxation times λ _k = 0.01, 0.1, 1, 10, and 100 seconds. The sum is k = 1 to k = 5. The sum of η _k is equal to zero shear viscosity, η ₀ . A high level branched block product index is a high value of η ₅ , which corresponds to a relaxation time of 100 seconds for zero shear viscosity. The viscosity fraction with a relaxation time of 100 seconds is η ₅ divided by zero shear viscosity, η ₀ . For the polymers of the present invention, the viscosity fraction with a relaxation time of 100 seconds is preferably at least 0.1, more preferably 0.4, and most preferably 0.8. In contrast, the 100 second chain viscosity fraction of conventional isotactic polypropylene is approximately 0.10 or less, and that of conventional propylene / ethylene copolymers is approximately 0.10 or less. Chains with long relaxation times cannot relax during the cycle time of small amplitude oscillatory shear experiments, leading to high zero shear viscosity.

  The branched block composition of the in-reactor blend of the present invention can include a wide variety of structural compositions that allow fine tuning of tensile properties over a wide range. While not wishing to be limited to any theory, in addition to the branched block structure composition, the crystalline polymer forms a hard inclusion (or crystal) within the soft matrix, thereby causing physical crosslinking. Are believed to form within the polymer blend. The presence of physical crosslinks promotes tensile properties. In order to be effective, the highly crystalline hard inclusion is preferably multi-block with low crystalline or amorphous chain segments. The low crystalline or amorphous chain segment should be long enough to span the distance between the two hard inclusions or to entangle other chain segments from other hard inclusions.

In one embodiment, the side branch and backbone components are immiscible so that the blend has a heterogeneous morphology. One advantageous heterogeneous blend includes a polymer component with lower crystallinity in the dispersed phase and a polymer with higher crystallinity in the continuous phase. For some applications, blends have a wide range of forms, since higher and lower crystallinity components can also be co-continuous. Alternatively, the in-reactor blend can have a heterogeneous form with a higher crystalline component in the dispersed phase and a less crystalline component in the continuous phase. In any case, the size of the individual domains of the dispersed phase is very small, and without adding any compatibilizer, the shortest length dimension for the dispersed phase is usually less than 5 μm, for example less than 2 μm, even less than 1 μm, etc. It is. Without wishing to be limited by any theory, it is believed that the reason for the small domain size is the presence of a branched block composition having the characteristics of both the first polymer and the second polymer component. In particular, it is believed that such molecules containing each segment of the polymer component act like a compatibilizer within the in-reactor blend. Due to the presence of the branched block composition, the immiscible components in the blend are compatible to the extent that a compatibilizer is not required and this fine form is achieved and retained. The presence of fine particles in the dispersed phase generally allows the dispersion of larger amounts of the dispersed phase within the polymer matrix, stabilizes the resulting morphology by preventing the agglomeration of the dispersed particles and enhances the mechanical properties of the blend. To do. This also allows for the production of softer in-reactor polymer blends.
Instead, the components on the side branches and backbone, and the individual components in the in-reactor blend are miscible. The polymer blend produced in the in-reactor thus has a homogeneous morphology. If all individual components can be crystallized within a limited range, they are at least partially co-crystallized.

  In one practical embodiment, the reactor blend of the present invention is composed of a propylene copolymer having at least one monomer selected from ethylene or C4-C12 alpha olefins, wherein the branches are composed of propylene homopolymer. Branched block copolymers. In another embodiment, both the backbone and branch of the branched block polymer are composed of propylene copolymer, and the difference in crystallinity between the copolymer in the backbone and branch is at least 5%, such as at least 10 %, For example at least 20%.

  The in-reactor polymer blends described herein can be produced using any suitable polymerization technique used in the art. Typically, the in-reactor polymer blends described herein use the process described in USSN 12 / 335,252 filed December 15, 2008, which is incorporated herein by reference. Can be generated. Polymerization methods include high pressure, slurry, gas, bulk, suspension, supercritical, or solution phase, or combinations thereof, using a single site metallocene catalyst system. The catalyst can be in the form of a homogeneous solution, supported, or a combination thereof. The polymerization can be performed in a continuous, semi-continuous or batch process and can include the use of chain transfer agents, scavengers, or other such additives deemed to be applicable.

Particularly preferred transition metal compounds for producing polymer blends useful herein are racemic metallocenes such as rac-dimethylsiladiyl (2-isopropyl, 4-phenylindenyl) ₂ zirconium dichloride; rac-dimethylsilayl Diyl (2-isopropyl, 4- [1-naphthyl] indenyl) ₂ zirconium dichloride; rac-dimethylsiladiyl (2-isopropyl, 4- [3,5-dimethylphenyl] indenyl) ₂ zirconium dichloride; rac-dimethylsiladyl (2-isopropyl, 4- [ortho - methyl - phenyl] indenyl) ₂ zirconium dichloride; rac- dimethylsilyl bis - (2-methyl, 4-phenyl indenyl) zirconium dichloride; rac-dimethyl-sila-diyl bis - (2-methylcarbamoyl , 4-naphthyl indenyl) zirconium dichloride; rac- dimethylsilanylbis diyl (2-isopropyl, 4- [3,5-di -t- butyl - phenyl] indenyl) ₂ zirconium dichloride; rac- dimethylsilanylbis diyl (2-isopropyl, 4- [orthophenyl-phenyl] indenyl) ₂ zirconium dichloride; rac-diphenylsiladiyl (2-methyl-4- [1-naphthyl] indenyl) ₂ zirconium dichloride; and rac-biphenylsiladiyl (2-isopropyl, 4- [3,5 di-t-butyl-phenyl] indenyl) ₂ zirconium dichloride. Alkylation variants of these metallocenes (eg di-methyl instead of dichloride) are also envisaged, which is usually indicated by the choice of catalyst activation system. These and other metallocene compositions are described in US Pat. Nos. 6,376,407; 6,376,408; 6,376,409; 6,376,410; 6,376,411 6,376,412; 6,376,413; 6,376,627; 6,380,120; 6,380,121; 6,380,122; No. 6,380,123; No. 6,380,124; No. 6,380,330; No. 6,380,331; No. 6,380,334; No. 6,399,723; , 825,372. These catalyst compounds can be activated by alumoxanes or non-coordinating anion activators such as those described on pages 30-34 of USSN 12 / 335,252. Preferred activators are: methylalumoxane; modified methylalumoxane; N, N-dimethylanilinium tetra (perfluorophenyl) borate; N, N-dimethylanilinium tetrakis (perfluoronaphthyl) borate; N, N N-dimethylanilinium tetrakis (perfluorobiphenyl) borate; N, N-dimethylanilinium tetrakis (3,5-bis (trifluoromethyl) phenyl) borate; triphenylcarbenium tetrakis (perfluoronaphthyl) borate Triphenylcarbenium tetrakis (perfluorobiphenyl) borate; triphenylcarbenium tetrakis (3,5-bis (trifluoromethyl) phenyl Borate, and triphenylcarbenium tetra (perfluorophenyl) borate.

  Particularly preferred catalysts include N-linked carbazol-9-yl substituted, bridged bis-indenyl metallocene compounds such as rac-dimethylsilylbis (2-methyl-4-carbazolyl-indenyl) zirconium dimethyl and the like. . These compositions are described in detail in US Pat. No. 7,812,104, which is incorporated herein by reference.

  A particularly useful catalyst / activator combination is rac-dimethylsilylbis (2-methyl-4-phenylindenyl) zirconium activated with methylalumoxane or N, N-dimethylanilinium tetrakis (perfluoronaphthyl) borate. Contains dimethyl.

Additives The in-reactor polymer blends described herein may contain one or more additives known in the art, such as toughening and non-reinforcing fillers, anti-scratch agents, plasticizers, antioxidants. Agents, heat stabilizers, extender oils, lubricants, antiblocking agents, antistatic agents, antifoggants, waxes, pigments, fire / flame retardants, dyes and colorants, and UV absorbers. Other additives include, for example, vulcanizing agents or curing agents, vulcanization accelerators or curing accelerators, cure retardants, processing aids, adhesive resins, and other processing aids known in the art of polymer compounding. . The list set forth herein is not intended to include all types of additives that can be utilized with the present invention. Upon reading this disclosure, one of ordinary skill in the art will understand that other additives may be utilized to enhance properties. As will be appreciated by those skilled in the art, the blends of the present invention can be modified to adjust the properties of the blend as desired. The above-mentioned additives may be added independently or may be incorporated into the additive or masterbatch. Such additives can comprise up to about 70%, more preferably up to about 50% by weight of the total composition.

  Fillers and extenders that can be utilized include conventional or nano-sized minerals such as calcium carbonate, clay, silica, talc, titanium dioxide, carbon black, mica, silicates, combinations thereof, and the like. Extender oils and plasticizers can also be used. Rubber processing oils are generally aromatic oils derived from paraffinic, naphthenic or petroleum fractions.

  The blowing agent can be incorporated or mixed into the polymer melt by any means known in the art, such as an extruder, stirrer, or blender. The blowing agent is usually mixed with the polymer melt under conditions sufficient to prevent a significant increase in the melt polymer material and generally uniformly disperse the blowing agent therein (eg, high pressure). The nucleating agent may be blended with the polymer melt prior to plasticization or melting, or may be dry blended with the polymer material.

  It is also known to add a small amount of particulate solid to the polymer prior to foaming, and this particulate solid acts as a seed to promote bubble formation. The particulate solid preferably has an average particle size of 0.1 μm to 200 μm, especially 1 μm to 50 μm. For example, any fine solid particles such as chalk, talc, and silica can be used. Preferably, talc is used. Useful amounts of microparticles can be up to 5 wt% (preferably 0.01-5 wt%, preferably 0.1 wt% -4 wt%) based on the total material in the blend. In certain preferred embodiments, a high melt strength foam is made in an extruder by using 1-3% by weight (more preferably about 2% by weight) of talc.

The blends of the present invention may also contain slip agents or mold release agents to promote moldability, preferably up to 10 wt% at 50 ppm, more preferably 50-5000 ppm, based on the weight of the composition. Even more preferably, it is present at 0.01-0.5 wt% (100-5000 ppm), even more preferably 0.1-0.3 wt% (1000-3000 ppm). Desirable slip additives include, but are not limited to, saturated fatty acid amides (eg, palmitamide, stearamide, arachidamide, behenamide, stearyl stearamide, palmitylpartamide, stearyl arachidamide); saturated ethylene- Bis-amides (eg stearoamide-ethyl-stearamide, stearoamide-ethyl-palmitamide, and palmitamido-ethyl-stearamide); unsaturated fatty acid amides (eg oleamide, erucamide, and linoleamide); unsaturated ethylene-bis-amide ( For example, ethylene-bis-stearamide, ethylene-bis-oleamide, stearyl-erucamide, erucamido-ethyl-el Amide, oleamide-ethyl-oleamide, erucamide-ethyl-oleamide, oleamide-ethyl-erucamide, stearamide-ethyl-erucamide, erucamide-ethyl-palmitamide, and palmitamide-palmitamido -Oleamide); glycols; polyether polyols (eg carbowax); aliphatic hydrocarbon acids (eg adipic acid and sebacic acid); aromatic or aliphatic hydrocarbon esters (eg glycerol monostearate and pentaerythritol monoole) Art); styrene-alpha-methylstyrene; fluoro-containing polymers such as polytetrafluoroethylene, fluoro oils, and fluorine Box); silicon compounds (e.g., silicone oil, silane and silicone polymers) including modified silicone and a cured silicone; including and mixtures thereof; sodium alkyl sulfates, alkyl phosphate esters; stearate, for example zinc stearate. The preferred slip additive is an unsaturated fatty acid amide, which is available from Crompton (Kenamid ™ grade) and Croda Universal (Crodamide ™ grade). Particularly preferred are erucamide and oleamide versions of unsaturated fatty acid amides. Preferred slip agents also include amides having the chemical structure CH ₃ (CH ₂ ) ₇ CH═CH (CH ₂ ) _x CONH ₂ , where x is 5-15. Particularly preferred amides include: 1) CH ₃ (CH ₂ ) ₇ CH═CH (CH ₂ ) ₁₁ CONH ₂ , which is erucamide or cis-13-docosenoamide (erucamide from Akzo Nobel Amides Co. Ltd. 2) oleylamide CH ₃ (CH ₂ ) ₇ CH═CH (CH ₂ ) ₈ CONH ₂ ; and 3) oleamide, which is also N-9-octadecenyl- Hexadecanamide, CH ₃ (CH ₂ ) ₇ CH═CH (CH ₂ ) ₇ CONH ₂ may be preferred. In another embodiment, stearamide is also useful in the present invention. Other preferred slip additives include those described in WO2004 / 005601A1.

  The polymer additive can also include a nanocomposite, which is a blend of polymers having one or more organoclays. Exemplary organoclays include phosphonium derivatives of ammonium, primary alkyl ammonium, secondary alkyl ammonium, tertiary alkyl ammonium, quaternary alkyl ammonium, aliphatic, aromatic or aryl aliphatic amines, phosphines or sulfides. Or one or more of a sulfonium derivative of an aliphatic, aromatic or arylaliphatic amine, phosphine, or sulfide. Furthermore, organoclays are montmorillonite, sodium montmorillonite, calcium montmorillonite, magnesium montmorillonite, nontronite, beidellite, vorcon score, laponite, hectorite, saponite, sauconite, magadite, kenyaite, sobokite, subindordite, stevensite, vermiculite. , Halloysite, aluminate, hydrotalcite, illite, rectolite, tarosovite, readykite, and / or fluorine mica.

When present, the organoclay is preferably included in the nanocomposite in an amount of 0.1 to 50% by weight based on the total weight of the nanocomposite. The stabilizing functional group can be selected from one or more of phenol, ketone, hindered amine, substituted phenol, substituted ketone, substituted hindered amine, and combinations thereof. The nanocomposite can further comprise at least one elastomeric ethylene-propylene copolymer, which is typically present in the nanocomposite in an amount of 1 to 70% by weight relative to the total composition.
Additives such as fillers and oils can be introduced into the in-reactor polymer blend either during the polymerization in either the first polymerization zone or the second polymerization zone. The additive can be added to the waste water from the second polymerization zone, but is preferably added into the polymer blend after removal of the solvent or diluent via the melt blend.

  In another embodiment, the blend has less than 5 wt% filler based on the weight of polymer and filler.

  Additional polymer can also be added to the in-reactor polymer blend. In one or more embodiments, the additional polymer comprises a thermoplastic resin or a thermoplastic elastomer. Exemplary thermoplastic resins include crystalline polyolefins. Suitable thermoplastic resins may also include copolymers of polyolefins with styrene, such as styrene-ethylene copolymers. In one or more embodiments, the thermoplastic resin is an ethylene or alpha-olefin such as propylene, 1-butene, 1-hexene, 1-octene, 2-methyl-1-propene, 3-methyl-1-pentene. , 4-methyl-1-pentene, 5-methyl-1-hexene, and mixtures thereof. Ethylene and propylene with ethylene and propylene and another alpha-olefin such as 1-butene, 1-hexene, 1-octene, 2-methyl-1-propene, 3-methyl-1-pentene, 4-methyl-1- Copolymers such as pentene, 5-methyl-1-hexene, or mixtures thereof are also envisioned. Specifically included are propylene and homo-polypropylene, impact, and random copolymers of ethylene or higher alpha-olefins described above. Preferably, the homopolypropylene has a melting point of at least 130 ° C., such as at least 140 ° C., preferably no more than 170 ° C., as determined by DSC analysis, at least 75 J / g, alternatively a heat of fusion of at least 80 J / g, and at least 50, Having a weight average molecular weight (Mw) of at least 100,000. The comonomer content for these propylene copolymers is usually from 1 to about 30% by weight of polymer (see, eg, US Pat. Nos. 6,268,438; 6,288,171; and 6,245,856). It is. Specifically, it includes a copolymer available under the trade name VISTAMAXX ™ (ExxonMobil, Houston Texas). Also suitable according to the present invention are blends or mixtures of two or more polyolefin thermoplastics, such as those described herein, or those having other polymer modifiers. These homopolymers and copolymers are suitable for any suitable polymerization technique known in the art, such as, but not limited to, conventional Ziegler-Natta type polymerization and, but not limited to, single site, metallocene catalysts, etc. It can be synthesized by using catalysis utilizing an organometallic catalyst.

Foamed Products The polymer blends of the present invention can be processed in a manner similar to any other polyolefin useful in the foaming process. Foam compositions can be produced by several methods, such as compression molding, injection molding, and a hybrid of extrusion and molding. This process can include the step of achieving a homogeneous or heterogeneous compound by mixing the polymer to form a melt with a blowing agent and other typical additives under heating. The components can be mixed and blended by any means known in the art using, for example, a Banbury, high intensity stirrer, 2 roll mill, and extruder. By adjusting the time, temperature, and shear rate, optimal dispersion without primary foaming can be ensured. High temperature mixing can cause primary foaming due to decomposition of the blowing agent or bubble collapse due to lack of structural stabilization. If the melting temperature is too low, foaming is limited because the material solidifies before the bubbles have the potential to fully expand. Sufficient temperature is desired to ensure good mixing of the polymer and dispersion of other components. The upper temperature limit for safe operation may vary depending on the starting decomposition temperature of the blowing agent utilized. The decomposition temperature of some blowing agents is lower than the polymer melting temperature. In this case, the polymer may be melt blended prior to mixing with the other component (s). The resulting mixture can then be combined with the components. An extruder with planned cooling / heating can also be utilized. The second half of the foam extruder is provided for melt cooling and intimate mixing of the polymer-blowing agent system. Molding can be performed after mixing. Sheet rolls or calender rolls are often used to make foam sheets that are appropriately sized. An extruder can be used to form the composition into pellets. Foaming can be performed in the compression mold at a temperature and time that completes the decomposition of the blowing agent. Pressure, molding temperature, and heating time can be controlled. Foaming can be performed in injection molding equipment by using the foamed composition in pellet form. The resulting foam can be further shaped to the final product dimensions by any means known in the art, such as by thermoforming and compression molding.

A nucleating agent may be blended into the polymer melt. By adjusting the feed rate of the foaming agent and nucleating agent, a relatively low density foam and small cell size is achieved, which results in a foam with thin cell walls.
Polyolefin foam is typically made by extrusion processes well known in the art. Preferably, the extruder is longer than the standard type and typically has an overall L / D ratio> 40 in either a single or tandem extruder configuration. Melting temperature is one of the most important process parameters in foam extrusion. Preferably, the melting temperature is in the range of about 130 ° C to 180 ° C.
In particular, the in-reactor polymer blends described herein are intended for use in producing automotive injection molded parts such as door panels, consoles, armrests, dashboards, seats, and ceilings, In particular, these parts comprise a foam core covered with a soft-feel and scratch-resistant membrane. Such parts can be formed using separate injection molding operations to produce cores and membranes, or can be produced in a single injection molding operation using commercially available multi-shot injection machinery. Can do.

  Those skilled in the art will appreciate that the steps outlined above may vary depending on the desired results. For example, an extruded sheet of the composition of the present invention can be thermoformed or blow molded as it is without cooling, thus eliminating the cooling step. Other parameters may also be different to achieve a finished composite product with desirable characteristics.

The foam material of the present invention preferably has a void volume of at least about 5%, more preferably at least about 10%, more preferably at least about 15%, more preferably still at least about 20%, even more preferably at least about 30%. Have capacity. Such void volume can significantly reduce the consumption of polymer material. In another set of embodiments, the material has a void volume of at least about 50%, more preferably at least about 60%, more preferably at least about 70%, and even more preferably at least about 75%. In this context, void volume means the initial void volume, ie the void volume immediately after extrusion to normal environmental conditions and cooling. The void volume is calculated from the foam density determined according to ASTM D1622-08.
Foamed products produced using the blends described herein are typically 800 kg / m ³ or less, preferably 600 kg / m ³ or less, more preferably 400 kg / m ³ , even more preferably 200 kg / m. It has a density of m ³ or less. Foam density is determined according to ASTM D1622-08.
Instead, foamed products produced using the blends described herein typically have more than 20% open cells, preferably about 30 to about 70% open cells in accordance with ASTM D2856-A. .
In another embodiment, foamed products produced using the blends described herein are typically greater than 50%, preferably greater than 70%, more preferably greater than 80%, according to ASTM D2856-A. Of closed cells.

Foamed products produced using the blends described herein typically have an average cell size of about 3 mm or less, preferably about 2 mm or less, preferably 1 mm or less, according to ASTM D3576-04. Instead, the bubble size is between 10 μm and 10 mm, preferably between 100 μm and 5 mm.
Another unique feature of foamed products produced using the blends described herein is the temperature range for a wide range of applications (or end uses). In one embodiment, the application temperature is between -40 and 160 ° C, preferably between -30 and 150 ° C, more preferably between -20 and 140 ° C. The in-reactor blend includes a high crystallinity propylene copolymer component having a melting point higher than 140 ° C. and a low crystallinity propylene copolymer component having a glass transition temperature as low as −50 ° C. Branched block cross-linked products are characterized by features derived from both high and low crystallinity propylene copolymers, such as low glass transition temperature of low crystallinity components and high melting temperature of high crystallinity polypropylene segments. Possess.

Use of Foamed Products The compositions of the present invention can be used for any known application related to molding or extrusion, including consumer goods, industrial products, construction materials, packaging materials, and automotive parts. For example, foamed products are used as weather seals for the automotive industry, and the purpose is to capture road noise, dust, dust, and moisture at various openings, such as window seals, door seals, and trunk seals. Can be used to decrease. The elastomeric properties of the in-reactor blend foam are adapted to the required shape, and when closed, the compressed foam prevents the entry of noise, dust, and moisture so that the intrusion of the automobile opening. Enables effective compression into gaps and corners at the opening.

For food packaging, PP foam provides a lightweight packaging solution with excellent grease / fat / oil resistance. Its high thermal stability means that the products can be microwaved and they give a “cold feel” during removal due to good thermal insulation.
In automotive applications, lightweight foam solutions help improve vehicle performance and fuel efficiency. As pressure on recycling of discontinued vehicles increases, solutions with recyclable foamed PP are a logical next step as single material solutions are explored and PP becomes the preferred polymer. PP foams have excellent moisture barriers and chemical resistance that are important for durability and functionality in the presence of hot oils, greases, or fuels. Its high thermal stability also opens up possibilities for hood applications.

  The foamable in-reactor blends of the present invention are also useful for automotive interior components such as equipment panels, door trim panels, and side pillars. The automotive industry is moving from parts that require multi-stage processes and manual assembly to simpler systems that utilize modern tools such as multi-shot injection molding machines that allow part integration. Automobile parts that involve creating a film foam system on a rigid substrate are often steadily assembled using various types of materials. The reactor product can achieve the desired functionality, such as foam properties, at lower manufacturing and assembly costs.

In another embodiment, the present invention relates to: (I) 90-100% by weight (preferably 92-99% by weight, preferably 95-97% by weight) propylene and 0 or more and less than 10% by weight (instead of 1-8% by weight, instead of 3-5% by weight) A comonomer (preferably ethylene, butene, hexene or octene) having a melting point of 120 ° C. or higher (preferably 130 ° C. or higher, preferably 135 ° C. or higher, preferably 140 ° C. or higher, preferably 150 ° C. or higher). One propylene polymer component;
(Ii) 30-90 wt% (preferably 35-85 wt%, preferably 40-80 wt%) propylene and 70-10 wt% (preferably 65-15 wt%, preferably 60-20 wt%) A second propylene having a Mw of 30,000 g / mol or more, preferably 50,000 g / mol or more, preferably 75,000 g / mol or more, comprising a comonomer (preferably ethylene, butene, hexene or octene) A foamable thermoplastic in-reactor blend comprising a polymer component, wherein the second propylene-containing polymer is at least 5% (preferably at least 10%, preferably) with the first polymer and optionally the first propylene-containing polymer. Preferably at least 15%, preferably at least 20%, preferably at least Unlike 0%) crystallinity, the second propylene containing, relative to one another, at least 5% (preferably at least 10%, preferably at least 20%, unlike preferably at least 30%) Tg,
The in-reactor polymer blend is preferably a blowing agent (preferably 0.01 to 10% by weight, preferably 0.1 to 5% by weight, preferably 0.5 to 3% by weight relative to the weight of the in-reactor polymer blend. %)
Prior to combination with the blowing agent, the polymer blend is
(A) a Tm of at least 120 ° C (preferably 130 ° C or higher, preferably 135 ° C or higher, preferably 140 ° C or higher, preferably 150 ° C or higher);
(B) a melt flow rate of 10 dg / min or more (preferably 20 dg / min or more, preferably 30 dg / min or more, preferably 40 dg / min or more);
(C) a breaking tensile strength of at least 8 MPa (preferably at least 10 MPa, preferably at least 12 MPa, preferably at least 15 MPa);
(D) Elongation at break of at least 200% (preferably 300% or more, preferably 400% or more, preferably 500% or more); and (e) Elongation viscosity is measured at strain rates of 1 sec ^-1 and 180 ° C. If 5 or more (preferably 8 or more, preferably 10 or more, preferably 15 or more, alternately 30 or more, having a ratio of elongation at break to linear viscosity at a strain rate of 1 s ^-1 to foam the blend The foamed product is 800 kg / m ³ or less (preferably 600 kg / m ³ or less, preferably 500 kg / cm ³ or less, preferably 400 kg / m ³ or less, preferably 300 kg / cm ³ or less, preferably 200 kg / m ^3. A foamable thermoplastic in-reactor blend having a density of:

2. The blowing agent is azodicarbonamide, azodiisobutyro-nitrile, benzenesulfone hydrazide, 4,4-oxybenzenesulfonyl semicarbazide, p-toluenesulfonyl semicarbazide, barium azodicarboxylate, N, N′-dimethyl-N, N′-di. Nitrosotephthalamide, trihydrazinotriazine, methane, ethane, propane, n-butane, isobutane, n-pentane, isopentane, neopentane, methyl fluoride, perfluoromethane, ethyl fluoride, 1,1-difluoroethane, 1,1 , 1-trifluoroethane, 1,1,1,2-tetrafluoro-ethane, pentafluoroethane, perfluoroethane, 2,2-difluoropropane, 1,1,1-trifluoropropane, perfluoropropane, perfluorobutene , Perfluorocyclobutane, methyl chloride, methylene chloride, ethyl chloride, 1,1,1-trichloroethane, 1,1-dichloro-1-fluoroethane, 1-chloro-1,1-difluoroethane, 1,1-dichloro- 2,2,2-trifluoroethane, 1-chloro-1,2,2,2-tetrafluoroethane, trichloromonofluoromethane, dichlorodifluoromethane, trichlorotrifluoroethane, dichlorotetrafluoroethane, chloroheptafluoropropane, Dichlorohexafluoropropane, methanol, ethanol, n-propanol, isopropanol, carbon dioxide, nitrogen, argon, water, air, nitrogen, helium, sodium bicarbonate, sodium carbonate, ammonium bicarbonate, ammonium carbonate, ammonium nitrite, N, N -Dimethyl-N, N'-dinitrosoterephthalamide, N, N'-dinitrosopentamethylenetetramine, azodicarbonamide, azobisisobutyronitrile, azocyclohexylnitrile, azodiaminobenzene, barium azodicarboxylate, benzenesulfonyl Hydrazide, toluenesulfonyl hydrazide, p, p′-oxybis (benzenesulfonyl hydrazide), diphenylsulfone-3,3′-disulfonyl hydrazide, calcium azide, 4,4′-diphenyldisulfonyl azide, and p-toluenesulfonyl azide The foamable thermoplastic in-reactor polymer blend of paragraph 1, comprising one or more.

3. Foaming aids (preferably salicylic acid, phthalic acid, stearic acid, nitric acid, urea or derivatives thereof) are preferably from 0.01 to 10% by weight, preferably 0. 0%, based on the weight of the in-reactor polymer blend. The foamable thermoplastic in-reactor polymer blend of paragraph 1 or 2 for use with 1 to 5 wt%, preferably 0.5 to 3 wt%).
4). Preferably a particulate solid having an average particle size of 0.1 μm to 200 μm, especially 1 μm to 50 μm (preferably up to 5% by weight, preferably 0.01-5% by weight, preferably 0.1% -4% by weight) And preferably the particulate solid is one or more of talc, silica, chalk or nanoclay, the foamable thermoplastic in-reactor polymer blend of any of paragraphs 1, 2, or 3.
5. The foamable thermoplastic in-reactor polymer blend of any of paragraphs 1-4, wherein the foam is foamed and the foam has a closed cell structure of 50% or more (preferably 70% or more, more preferably 80% or more).
6). Paragraphs 1 to 1, wherein the foam is foamed and the foam has an average cell size of 3 mm or less (preferably about 2 mm or less, preferably 1 mm or less, instead the cell size is between 10 μm and 10 mm, preferably between 100 μm and 5 mm). 5. The foamable thermoplastic in-reactor polymer blend of any of 5.

7. The expandable thermoplastic in-reactor polymer blend of any of paragraphs 1-6, having a heat of fusion of 30 J / g or greater, preferably 40 J / g or greater.
8. The foamable thermoplastic in-reactor polymer blend of any of paragraphs 1-7 having a heat of fusion of 80 J / g or less, preferably 70 J / g or less.
9.4000 Pa. s or less (preferably 3000 Pa.s or less, more preferably 2000 Pa.s or less, even more preferably 1500 Pa.s or less), where the complex viscosity is an angular frequency of 0.01 to 100 rad / s. The foamable thermoplastic in-reactor polymer blend of paragraph 1, measured at 190 ° C. over a range.
10. The foam of paragraph 1, having a ratio of elongation at break to linear viscosity of 3 or greater (alternatively 5 or greater, alternatively 10 or greater) when the elongational viscosity is measured at a strain rate of 5 sec ^-1 and a temperature of 180 ° C. Thermoplastic in-reactor polymer blend.
11. (A) mixing the foaming agent and the melt foamable blend of any of paragraphs 1-10, (b) expanding the foamable mixture such that the foaming agent expands in the mixture to form a foam. A process for producing a foamed polyolefin product, comprising a step of treating, and (c) obtaining a foamed product having a density of 800 kg / m ³ or less.

12 The method of paragraph 11, wherein the melt-foamable mixture is heated or pressurized to cause foaming.
13. The method of paragraph 11, wherein the melt-foamable mixture is extruded or molded.
14 A foamed product comprising the foamed in-reactor blend of any of paragraphs 1-10, or the product of any of paragraphs 11, 12, or 13.
15. Use of the foamed product of paragraph 14 as an automotive part.

  The invention will now be described more specifically with reference to the accompanying non-limiting examples.

Experimental Section Using the following DSC procedure according to ASTM D3418-03, peak melting point Tm (also called melting point), peak crystallization temperature, Tc (also called crystallization temperature), glass transition temperature (Tg), heat of fusion (ΔHf or Hf) and crystallinity (percent) were determined. Differential scanning calorimetry (DSC) data was obtained using a TA Instruments model Q100 instrument. A sample weighing approximately 5-10 mg was sealed in an aluminum sealed sample pan. DSC data was recorded by first slowly heating the sample to 200 ° C. at a rate of 10 ° C./min. The sample was kept at 200 ° C. for 2 minutes, then cooled to −90 ° C. at a rate of 10 ° C./minute, followed by isothermal heating for 2 minutes and 200 ° C. at 10 ° C./minute. Both the first and second cycle heat events were recorded. The area under the endothermic peak was measured and used to determine heat of fusion and percent crystallinity. Crystallinity (percent) using the formula [area under melting peak (joule / gram) / B (joule / gram)] ^* 100, where B is the heat of fusion for a 100% crystalline homopolymer of the main monomer component Calculate These values for B are obtained from Polymer Handbook, Fourth Edition, published by John Wiley and Sons, New York 1999, except that a value of 189 J / g is used as the heat of fusion for 100% crystalline polypropylene. The value of / g shall be used for the heat of fusion for 100% crystalline polyethylene. The melting and crystallization temperatures reported here were obtained during the first cooling / second heating cycle unless otherwise stated.

  All peak crystallization temperatures and peak melting temperatures were reported for polymers showing multiple endothermic and exothermic peaks in the first cooling cycle and the second heating cycle. The heat of fusion for each endothermic peak was calculated individually. The sum of heat of fusion from all endothermic peaks is used to calculate the degree of crystallinity (percent). Some of the produced polymer blends show a second melting / cooling peak that overlaps the first peak, and these peaks together are considered a single melting / cooling peak. The highest of these peaks is considered the peak melting temperature / crystallization point. For amorphous polymers with relatively low levels of crystallinity, the melt temperature is usually measured and reported during the first heating cycle. Prior to DSC measurements, samples were aged (usually kept at ambient temperature for a period of 2 days) or annealed to maximize the level of crystallinity.

  Morphological data was obtained using an atomic force microscope (AFM) in the tapping phase. All samples were analyzed within 8 hours after the cryogenic surface finish to prevent sample relaxation. During the cryogenic surface finish, the specimen was cooled to -130 ° C and cut with a diamond knife in a Reichert cryogenic microtome. They were then warmed to ambient temperature without forming a condensation by storing them in a resolution mechanism under flowing dry nitrogen gas. Finally, the surface-finished specimen was inserted into a small steel vise for AFM analysis. AFM measurements were performed in air on a NanoScope Dimension 3000 scanning probe microscope (Digital Instrument) using a rectangular 225-mm Si cantilever. The cantilever stiffness was about 4 N / m and the resonant frequency was about 70 kHz. The free vibration amplitude was high, ranging from 80 nm to 100 nm, and the RMS was set at 3.8 volts. The setpoint ratio was maintained at a value of 0.5 or less, and the contact setpoint was adjusted as specified to ensure resilient contact with the positive phase shift. The cantilever was run at or slightly below its resonant frequency.

  Various sample forms were also examined using a scanning electron microscope (SEM, JSM-840). For blending, the sample is first cut into flakes in liquid nitrogen and then the surface is etched in heptane at room temperature for different times ranging from 30 seconds to 48 hours depending on the blend composition. Thus, an elastomer phase for SEM observation was taken out. For the foam, the test surface was freeze fractured in liquid nitrogen and then directly observed by SEM.

The ethylene content of the ethylene / propylene copolymer was determined using FTIR by the following technique. A thin homogeneous film of polymer compressed at a temperature of about 150 ° C. was affixed to a Perkin Elmer Spectrum 2000 infrared spectrophotometer. Samples were recorded for full spectrum of 600cm ^-1 ~4000cm ^-1, and calculate the area and about 732 cm ^-1 ethylene band area under propylene band at about 1165 cm ^-1 in the spectrum. The baseline integration range for the methylene rocking band is nominally from 695 cm ⁻¹ to a minimum between 745 and 775 cm ⁻¹ . For polypropylene bands, the baseline and integration range is nominally 1195 to 1126 cm ⁻¹ . The ethylene content (% by weight) was calculated according to the following formula:
Ethylene content (% by weight) = 72.698−86.495X + 13.669X ²
(Wherein, a X = AR / (AR + 1 ), AR is the area to the peak at about 1165 cm ^-1, a ratio to the area of a peak at about 732 cm ^-1).

^In conducting the ¹³ C NMR studies, samples were prepared by adding about 0.2-0.4 g of sample to about 3 ml of deuterated tetrachloroethane in a 10-mm diameter NMR tube. The sample was dissolved and homogenized by heating the tube and its contents to 140 ° C., then the sample solution was placed in an NMR spectrometer with the probe temperature set at 125 ° C. Data was collected using a Varian Unity Plus® 400 MHz spectrometer that corresponds to a ¹³ C resonance frequency of 100.5 MHz. Data was acquired using 4000 transients per data file with a 6 second pulse repetition delay. Multiple data files were added together to achieve the maximum signal-to-noise ratio for quantitative analysis. The spectral width is 25,000 Hz and the minimum file size is 32K data points.

  A description of the data on 1-hexene contents is given in Kissin and Brandolini (Macromolecules, 24, 2632, (1991)), Folini, et al., (Macromol. Chem. Phys., 201, 401, 2000) and Resconi, et Based in part on the peak configuration provided in al., (Chem. Rev., 100, 1253, 2000). The instrument composition was used to determine the sample composition.

The presence of branched block structures in the in-reactor polymer blends of the present invention can be detected using nuclear magnetic resonance spectroscopy ( ¹³ C NMR). In both the first and second polymerizations, a branched block structure can be made by inserting a portion of the vinyl group on the polymer chain end. These long chain branches are of the “Y” type, with three chains contacting at a single methine carbon. A peak corresponding to methylene adjacent to these branch points is found between 44 and 45 ppm. The arrangement of polypropylene chains relative to long chain branches is discussed in Weng, Hu, Dekmezian, and Ruff (Macromolecules 2002, 35, 3838-3843). Methylene is found at 44.88, 44.74, and 44.08 ppm relative to the propylene branching between the propylenes in the backbone. Branched methine is found at 31.84 ppm. For ethylene long chain branches in ethylene, Randall (Polymer Reviews 29 (2), pp. 201-317, (1989)) describes a method for measuring these. In the polymers of the present invention, long chain branching between the ethylene / propylene chain and the isotactic polypropylene chain was found at 44.68, 44.83, 44.92 ppm.

  Polymer Laboratories Model 220 high temperature SEC with on-line differential refractive index (DRI), light scattering, and viscometer detector (also called GPC-3D) was used to determine molecular weight (number average molecular weight (Mn)), weight average molecular weight ( Mw), and z-average molecular weight (Mz)) were determined. Three Polymer Laboratories PLgel 10m Mixed-B columns were used for the separation, using a flow rate of 0.54 ml / min and a nominal injection volume of 300 μL. The detector and column were contained in an oven maintained at 135 ° C. The light scattering detector was a high temperature miniDAWN (Wyatt Technology, Inc.). The main components were an optical flow cell, a 30 mW, 690 nm laser diode light source, and an array of three photodiodes installed at collection angles of 45 °, 90 °, and 135 °. The flow emerging from the SEC column is directed to the miniDAWN optical flow cell and then to the DRI detector. The DRI detector is an integral part of the Polymer Laboratories SEC. The viscometer is a high temperature viscometer purchased from Viscotek Corporation and includes four capillaries arranged in a Wheatstone bridge configuration with two pressure transducers. One transducer measures the total pressure drop across the detector, and the other transducer located between the two sides of the bridge measures the differential pressure. The viscometer was located inside the SEC oven, after the DRI detector. Details of these detectors as well as their calibration are described in, for example, T. Sun, P. Brant, RR Chance, and WW Graessley, in Macromolecules, Volume 34, Number 19, 6812-, incorporated herein by reference. 6820, (2001).

  The solvent for the SEC experiment is 6 grams of butylated hydroxytoluene (BHT) as an antioxidant, added to 4 liter bottles of 1,2,4 trichlorobenzene (TCB) (Aldrich Reagent grade) to solubilize BHT. Prepared by waiting until. The TCB mixture was then filtered through a 0.7 micron glass prefilter followed by a 0.1 micron Teflon filter. There was an additional on-line 0.7 micron glass prefilter / 0.22 micron Teflon filter assembly between the high pressure pump and the SEC column. The TCB was then degassed with an online degasser (Phenomenex, model DG-4000) before entering the SEC. A polymer solution was prepared by placing the dry polymer in a glass container, adding the desired amount of TCB, and then heating the mixture at 160 ° C. with continuous stirring for about 2 hours. All amounts were measured gravimetrically. The TCB density used to express the polymer concentration in mass / volume units was 1.463 g / ml at room temperature and 1.324 g / ml at 135 ° C. Injection concentrations ranged from 1.0 to 2.0 mg / ml, with lower concentrations used for higher molecular weight samples.

  Crystallographic fractionation (CRYSTAF) was performed using a CRYSTAF 200 unit, commercially available from PolymerChar, Valencia, Spain. Samples were dissolved in 1,2 dichlorobenzene at 160 ° C. at a polymer concentration of about 0.2-1.0 mg / ml for about 1 hour and stabilized at 95 ° C. for about 45 minutes. The sampling temperature was in the range of 95-30 ° C or 95-0 ° C with a cooling rate of 0.2 ° C / min. The polymer solution concentration was measured using an infrared detector. As the polymer crystallized, the temperature decreased, but the cumulative soluble concentration was measured. The analytical derivative of the cumulative profile reflects the crystallinity distribution of each polymer component of the in-reactor polymer blend. CRYSTAF peak temperature and area were identified by the peak analysis module included in the CRYSTAF software. The CRYSTAF peak detection routine identifies the peak temperature as the maximum in the dw / dT curve and the area between the maximum positive inflection points on either side of the identified peak in the derivative curve.

  Shore hardness was determined according to ISO 868.

Stress-strain properties were determined for in-reactor polymer blends according to ASTM D1708. Samples were prepared using compression molded plaques. Tensile properties were measured on an Instron ™ model 4502 equipped with a 22.48 lb (10.2 kg) load cell and a pneumatic jaw fitted with a serrated grip surface. Deformation was performed at a constant crosshead speed of 5.0 inches / minute with a data sampling rate of 25 points / second. The initial elastic modulus, yield stress and strain (if obvious), peak stress, fracture tensile strength, and fracture strain were calculated. A minimum of 5 specimens from each plaque were tested and the results reported as an average value. All stresses quoted were calculated based on the original cross-sectional area of the specimen, not taking into account the reduction in cross-section as a function of increasing strain. The tensile strength is defined as the maximum tensile stress. The tensile strength is also called the final strength. Toughness is defined as the ability to absorb energy applied before the polymer breaks. The area under the stress-strain curve is used as a measure of toughness.
Melt flow rate (MFR) was determined according to ASTM D1238 using a load of 2.16 kg and a temperature of 230 ° C.

  Dynamic Mechanical Thermal Analysis (DMTA) examines the behavior of viscoelastic materials according to temperature and frequency dependent behavior. Application of a small stress causes deformation (strain) of the material. The amount of deformation resulting from the applied stress yields information about the material's modulus; its stiffness and damping characteristics. DMTA is a controlled stress device in which stress is applied in a sinusoidal manner, and provides a comparison between sinusoidal response and time. As a result of applying sinusoidal stress, the material responds in a manner of elasticity (energy conservation) and viscosity (energy dispersion). DMTA separates these reactions into two different modulus values: elastic modulus (E ′) and loss modulus (E ″), and measures these coefficients from the glass region, the horizontal region to the end region during the temperature sweep. The response of the viscoelastic material is a phase mismatch with the input signal at the angle delta (δ), the tangent of this angle (tan δ) is equal to the ratio E ″ / E ′ and the relative damping of the material It is a valuable indicator of Noh. Any peak in tan δ corresponds to a region where the material properties change very rapidly. This material undergoes transitions or relaxations such as Tg (glass transition temperature) and other relaxations. For purposes of the present invention and its claims, Tg shall be determined by DSC and DMTA shall be used if Tg is not determined by DSC.

  Dynamic shear melt rheology data was obtained using an advanced Rheometrics Expansion System (ARES) using parallel compression plates (diameter = 25 mm) at several temperatures ranging from 150 to 210 ° C. using new compression molded samples at each temperature. ). Measurements were made over an angular frequency in the range of 0.01-100 rad / s. Depending on molecular weight and temperature, strains of 10% and 15% were used to verify the linearity of the reaction. A stream of nitrogen was circulated through the sample oven to minimize chain extension or crosslinking during the experiment. All samples were compression molded at 190 ° C. and no stabilizer was added. If the strain amplitude is small enough and the material behaves linearly, a sinusoidal shear strain is applied to the material. The generated steady state stress will also oscillate sinusoidally at the same frequency, but can be shown to shift at a phase angle δ relative to the distorted wave. The stress leads the strain by δ. For a purely elastic material, δ = 0 ° (stress is in a strained phase) and for a purely viscous material, δ = 90 ° (stress is 90 ° above strain) Only leading, but the stress is in a phase with strain rate). For viscoelastic materials, 0 ° <δ <90 °.

  The extensional viscosity (also called extensional viscosity) was measured using a SER-HV-A01 geometry (Xpansion Instruments, LLC) attached to a strain-controlled rheometer (ARES, Rheometric Scientific).

(Examples 1-3)
For these examples, Example 1 produces polypropylene in a first reactor and a propylene / hexene copolymer in a second reactor, and Examples 2 and 4 produce polypropylene in a first reactor. Example 3 produces a propylene / ethylene copolymer in a second reactor, Example 3 produces a propylene / ethylene / 1,9 decadiene copolymer in a first reactor and a propylene / ethylene copolymer in a second reactor To demonstrate the use of a series reactor operating in a continuous stirred-tank solution process. The first reactor was 0.5 liter and the second reactor was 1 liter. Both were stainless steel autoclave reactors equipped with a stirrer, a water cooling / steam heating element with a temperature controller, and a pressure controller. Solvents, monomers, such as ethylene and propylene, were purified by first passing through a three column purification system. The purification column was periodically regenerated whenever there was evidence of lower activity polymerization.

  The solvent feed to the reactor was measured with a mass-flow meter. The Pulsa feed pump controlled the solvent flow rate and increased the solvent pressure to the reactor. The compressed, liquefiable propylene feed was measured with a mass flow meter and the flow was controlled with a Pulsa feed pump. 1,9 decadiene was diluted with toluene. The feed rate of diluted 1,9 decadiene and hexene was controlled using an Eldex metering pump. Solvent and monomer were first fed into the manifold. In-house supplied ethylene was delivered as a gas solubilized in the chilled solvent / monomer mixture in the manifold. The solvent and monomer mixture was then cooled to about −15 ° C. by passing it through a cooler before feeding it into the reactor via a single tube. The ethylene flow rate was metered through a Brookfield mass flow controller. The collected sample was first air-dried in a hood to evaporate most of the solvent and then dried in a vacuum oven at a temperature of about 90 ° C. for about 12 hours. The yield was obtained by weighing the vacuum oven dried sample. Conversion was calculated based on polymer yield and the amount of monomer fed to the reactor. All reactants were run at a pressure of about 2.4 MPa-g.

  In Examples 1, 2, and 4, N, N-dimethylanilinium tetrakis (heptafluoro-2-naphthyl) borate (activator 1) was used in 900 ml toluene at a molar ratio of about 1: 1, and rac -Dimethylsilylbis (2-methyl-4-phenylindenyl) zirconium dimethyl catalyst (catalyst A) was preactivated. In Example 3, the catalyst was rac- preactivated with N, N-dimethylanilinium tetrakis (pentafluorophenyl) borate (activator 2) in a molar ratio of about 1: 1 in toluene (900 ml). Dimethylsilylbis (2-methyl-4-carbazole-indenyl) zirconium dimethyl (Catalyst B). All catalyst solutions were kept in an inert atmosphere with a water content greater than 1.5 ppm and pumped into the reactor with a metering pump. Tri-n-octyl aluminum (TNOA) solution was used as a scavenger. By adjusting and optimizing the scavenger feed rate, good yields were achieved at the start of each run.

  Propylene, isohexane, catalyst solution and scavenger solution were all initially fed to the reactor. The contents of the first reactor flow into the second reactor. Optionally, additional propylene and ethylene were fed to the second reactor. Detailed reaction conditions and polymer properties are listed in Table 1. The molecular weights reported in Table 1 were obtained from a light scattering detector.

  Example 1 utilizes catalyst A and activator 1 to produce polypropylene in a first reactor, propylene / hexene copolymer in a second reactor, and feed additional catalyst A to the second reactor. Demonstrates the use of a series reactor operating in a continuous stirred tank solution process. A portion of the macromonomer produced in the first reactor was incorporated into the polymer made in the second reactor. Examples 2 and 4 utilized the same process used in Example 1, except that the propylene / ethylene copolymer was made in the second reactor. The preactivated catalyst solution used in Example 2 was aged for about 8 hours in a dry box before the polymerization was run. Example 3 is for producing a propylene / ethylene / 1,9-decadiene macromonomer (terpolymer) in a first reactor and a propylene / ethylene copolymer in a second reactor using the same catalyst. The process was demonstrated. A branched block composition was produced by incorporating a portion of the propylene / ethylene / 1,9-decadiene macromonomer into the propylene / ethylene copolymer chain. In Example 3, a higher crystalline polymer was produced in the second reactor.

  The polymer blend of Example 3 has a relatively low melting point, 121.6 ° C., relative to the isotactic polypropylene portion, which does not completely consume the ethylene from the first reactant, It was suggested that it flowed into the polymerization reactor.

For the polymer blends produced in Examples 1, 2, and 3, microamplitude oscillating shear data was collected at a temperature of 190 ° C. over a frequency range of 0.01-100 rad / s. For Examples 1 and 2, when the angular frequency is changed from 0.01 to 100 rad / s, the shear thinning measured by complex viscosity is slight. The ratio of complex viscosity at a frequency of 100 rad / s to viscosity at a frequency of 0.01 rad / s was 0.34 and 0.52 for the materials produced in Examples 1 and 2, respectively. Significant shear thinning was observed for the polymer produced in Example 3. For the polymer blend produced in Example 3, the plot of loss angle versus frequency was substantially below 90 °, which showed extensive branching. The loss angle was relatively independent of frequency and varied between 73 ° and 51 ° as the frequency was changed from 0.01 to 100 rad / s. This is a gel-like behavior and exhibits extensive branching. The critical relaxation index for Example 3 was 0.567, which is also typical of a highly branched reactor blend. Example 3 showed a high amount of shear thinning. The ratio of complex viscosity at a frequency of 100 rad / s to complex viscosity at a frequency of 0.01 rad / s was 0.049. The plot of log (kinematic viscosity) versus log (frequency) versus Example 3 has a secant slope of -0.328, indicating that a branched block structure is present.
The polymer blends produced in Examples 1, 2, and 3 were compressed into plaques for tensile testing according to the procedure described above. The strain-stress characteristics of the products are listed in Table 1. For Example 3, the fracture stress was 21.5 MPa compared to 16.2 MPa for the stress at the yield point. This increase in stress after formation is due to strain hardening that occurs as the branch chain is stretched between the crystalline domain and the branch point. The fracture strain was 721%, which is typical for ethylene-propylene elastomers. Strain hardening was typical of cross-linked elastomers and showed the presence of extensive grafts and long chain branches.
The polymer blend produced in Example 1 is a fraction eluting between 60-80 ° C. with a peak temperature of 71 ° C., and a solution when fractionated using CRYSTAF according to the procedure described above. Has a fraction. The fraction corresponding to the highest temperature peak is called the highly crystalline fraction.

The extensional viscosity was measured using a SER-HV-A01 configuration (Xpansion Instruments, LLC) with a strain-controlled rheometer (ARES, Rheometric Scientific). The elongational viscosity of the polymer blend was measured at 4 constant Henky strain rates in a uniaxial, elongational flow at a constant temperature of 180 ° C. As a comparative example, a commercially available impact copolymer PP7032E2 (identified as PP1 in FIG. 1), available from ExxonMobil Chemical Company, Houston Texas, was also tested for extensional viscosity. PP7032E2 has an MFR (2.16 kg, 230 ° C.) of 4 dg / min and a tensile strength of 24 MPa at yield (50 mm / min, ASTM D638). As shown in FIG. 1, strong strain hardening was observed for the polymer blends produced in Examples 1 and 2. For the polymer blend of Example 1, the ratios of elongation at break to linear viscosity at strain rates of 1 and 10 sec ⁻¹ were 11.48 and 8.97, respectively. For the polymer blend of Example 2, the ratios of elongation at break to linear viscosity at strain rates of 1 and 10 sec ^-1 were 50.84 and 51.55, respectively.

  The data plot in FIG. 1 demonstrates the melt viscosity difference between the polymer blend of the present invention and Comparative Example PP1. Comparative polymer PP1 did not exhibit strain hardening and behaved as a linear viscoelastic material. The different behaviors exhibited by the in-reactor polymer blends of the present invention are fairly clearly the result of these different compositions and molecular structures.

The polymer blends and PP1 produced in Examples 1, 2, and 4 were subjected to foam testing. The blend for the injection foaming experiment was first prepared using a small co-rotating twin screw extruder (Leistritz ZSE18HP-40D). The barrel temperature profile was 120-180 ° C. and the feed rate was set at 100 rpm. Residual water was removed by pelletizing the extrudate and drying under vacuum at 40 ° C. for 12 hours. These were then prepared for rheology testing by compression molding at 180 ° C. under nitrogen for 2 minutes using a 3 ton pressure load, the sample being 25 mm diameter and about 1.5 mm thick. Disc and a sheet having a thickness of 0.65 to 1 mm.
Irganox B225 (from Ciba Specialty Chemicals Corp.) was added to the blend (1.0 wt%) to avoid any thermal degradation. Azodicarbonamide (AC) from Aldrich Chemical was used as the chemical blowing agent.

  The injection foaming test was performed with an all-electric injection molding machine (Sumitomo SE50S, screw diameter = 32 mm). An injection rate of 120 mm / sec was used. By using a rectangular mold with only one sprue installed at one end, it was possible to investigate the bubble structure moving at different distances along the injection direction. Two locations were selected 35 mm and 90 mm away from the injection port. Because 35 mm is close to the sprue, the sample will typically be subjected to a relatively high melt pressure and bubble nucleation may be affected. On the other hand, 90 mm is far from the injection port and the sample has more free space for foaming and therefore the bubble structure should be different from that of the front. 1% by weight AC was used for foaming and this was dry blended directly with the polymer material before being placed in the hopper.

FIG. 2 shows the cellular structure of the injected foam for the polymer blends made in Examples 1, 2, and 4. Images were obtained using SEM and the test surface was frozen and broken with liquid nitrogen. Both uniform cell size and good cell structure were observed for Examples 1 and 2. Further inspection of the microscopic image of the foamed product from Example 2 shows that the bubbles are almost spherical at both 35 mm and 90 mm from the injection port. As a comparative example, PP7032E2 (referred to as PP1 in FIG. 2), a super high impact copolymer from ExxonMobil, was also tested for foaming. PP7032E2 has an MFR of 4 dg / min, a tensile strength of 24 MPa with a yield (50 mm / min, ASTM D638). PP1 exhibits a poor cell structure in both cell uniformity and cell density.
FIG. 2 shows the cell structure of the injected foam component at two different locations away from the injection port. Injection conditions: Melting temperature = 210 ° C., mold temperature = 25 ° C., cooling time = 30 seconds, reverse pressure = 2 MPa, injection speed = 120 mm / second, injection size = 31 mm (about 83% of all molds). (A) Example 1 at 35 mm from the injection port; (b) Example 2 at 35 mm from the injection port; (c) Example 4 at 35 mm from the injection port; (d) PP1 at 35 mm from the injection port ( (For comparison); (e) Example 1 at 90 mm from injection; (f) Example 2 at 90 mm from injection port; (g) Example 4 at 90 mm from injection port; and (h) 90 mm from injection port. PP1 (for comparison).

  All documents mentioned herein, including any priority documents and / or test procedures, are hereby incorporated by reference to the extent not inconsistent with this text, provided that Any priority documents that are not listed in the application or application filed in are not incorporated herein by reference. While the form of the invention has been illustrated and described, as obvious from the foregoing general description and specific embodiments, various modifications can be made without departing from the spirit and scope of the invention. it can. Accordingly, the present invention is not intended to be limited thereby. Similarly, the term “comprising” is considered synonymous with the term “including” for the purposes of Australian law. Similarly, whenever a transition phrase “comprising” precedes a composition, element, or group of elements, the transition phrase “essentially ~ In the same composition or group of elements as those preceded by “consisting essentially of”, “consisting of”, “selected from the group consisting of”, or “is”. Assume that there is, and vice versa.

Claims (20)

(A) a first propylene polymer component comprising 90-100% by weight propylene and 0 to less than 10% by weight comonomer and having a Tm of 120 ° C. or higher;
(B) comprising 30 to 90 wt% propylene and 70 to 10 wt% comonomer, having a Mw of 30,000 g / mol or more and having a crystallinity different from the first polymer by at least 5%, A propylene polymer component of;
(C) a foamable thermoplastic in-reactor polymer blend comprising from 0 to about 10% by weight of blowing agent relative to the total material in the blend, prior to being combined with the blowing agent;
(I) a Tm of at least 120 ° C;
(Ii) a melt flow rate of 10 dg / min or more;
(Iii) a tensile strength of at least 8 MPa;
(Iv) elongation at break of at least 200%; and (v) when the extensional viscosity is measured at a strain rate of 1 s ⁻¹ and 180 ° C. and has a ratio of the elongation at break of 5 or more to the linear viscosity; A foamable thermoplastic in-reactor polymer blend wherein, when the blend is foamed, the foamed product has a density of 800 kg / m ³ or less.   The blowing agent is azodicarbonamide; azodiisobutyro-nitrile; benzenesulfone hydrazide; 4,4-oxybenzenesulfonyl semicarbazide; p-toluenesulfonyl semicarbazide; barium azodicarboxylate; N, N′-dimethyl-N, N′-dinitroso Terephthalamide; Trihydrazinotriazine; Methane; Ethane; Propane; n-Butane; Isobutane; n-Pentane; Isopentane; Neopentane; Methyl fluoride; Perfluoromethane; Ethyl fluoride; 1,1-Difluoroethane; 1,1,1,2-tetrafluoro-ethane; pentafluoroethane; perfluoroethane; 2,2-difluoropropane; 1,1,1-trifluoropropane; perfluoropropane; perfluoro butane Perfluorocyclobutane; methyl chloride; methylene chloride; ethyl chloride; 1,1,1-trichloroethane; 1,1-dichloro-1-fluoroethane; 1-chloro-1,1-difluoroethane; 1,1-dichloro-2, 2,2-trifluoroethane; 1-chloro-1,2,2,2-tetrafluoroethane; trichloromonofluoromethane; dichlorodifluoromethane; trichlorotrifluoroethane; dichlorotetrafluoroethane; chloroheptafluoropropane; dichlorohexa N-propanol; carbon dioxide; nitrogen; argon; water; air; nitrogen; helium; sodium bicarbonate; sodium carbonate; ammonium bicarbonate; Methyl-N, N'-dinitrosoterephthalamide; N, N'-dinitrosopentamethylenetetramine; azodicarbonamide; azobisisobutyronitrile; azocyclohexylnitrile; azodiaminobenzene; barium azodicarboxylate; benzenesulfonylhydrazide 1; toluenesulfonyl hydrazide; p, p′-oxybis (benzenesulfonyl hydrazide); diphenylsulfone-3,3′-disulfonyl hydrazide; calcium azide; 4,4′-diphenyldisulfonyl azide; and 1 of p-toluenesulfonyl azide The foamable thermoplastic in-reactor polymer blend of claim 1 comprising one or more.   The foamable thermoplastic in-reactor polymer blend of claim 1 or 2, wherein the blowing agent is present in the composition from about 0.01 to about 10% by weight, based on the total material in the blend.   4. A foamable thermoplastic in-reactor polymer blend according to claim 1, 2 or 3, wherein a foaming aid is used with the foaming agent.   The foaming aid is used with a foaming agent, and the foaming agent is selected from the group consisting of salicylic acid, phthalic acid, stearic acid, nitric acid, urea and derivatives thereof. Foamed thermoplastic in-reactor polymer blend.   6. A foamable thermoplastic inreactor polymer blend according to claim 1, 2, 3, 4, or 5, wherein when the blend is foamed, the foam has a closed cell structure of 50% or more. When foaming the blend, foam has a density of 600 kg / m ³ or less, expandable thermoplastic in a reactor polymer blend of any one of claims 1 to 6.   8. A foamable thermoplastic inreactor polymer blend according to any of claims 1 to 7, wherein when the blend is foamed, the foam has an average cell size of 1 mm or less.   The foamable thermoplastic in-reactor polymer blend according to any of claims 1 to 8, having a Tm of 135 ° C or higher.   10. A foamable thermoplastic in-reactor polymer blend according to any of claims 1 to 9, having a heat of fusion of 30 J / g to 80 J / g.   The foamable thermoplastic in-reactor polymer blend according to any of claims 1 to 10, further comprising one or more particulate solids.   When the complex viscosity is measured at 190 ° C. over an angular frequency range of 0.01 to 100 rad / s, 4000 Pa.s. 12. A foamable thermoplastic in-reactor polymer blend according to any of claims 1 to 11 having a complex viscosity of s or less. The foaming heat according to any one of claims 1 to 12, wherein the elongational viscosity has a ratio of the elongational viscosity at break of 3 or more to the linear viscosity when measured at a strain rate of 5 seconds ^-1 and a temperature of 180 ° C. Plastic in-reactor polymer blend.   14. A foamable thermoplastic in-reactor polymer blend according to any of claims 1 to 13 having a melt flow rate of 20 dg / min or more. (A) mixing a blowing agent with molten polyolefin to form a foamable mixture;
(B) forming the foamable mixture such that the foaming agent expands in the mixture to form a foam, and (c) obtaining a foamed product having a density of 800 kg / m ³ or less. A process for producing a foamed polyolefin product, wherein the molten polyolefin is a foamable thermoplastic in-reactor polymer blend according to any of claims 1-14.   The polymer blend has a Tm of 135 ° C. or higher, a heat of fusion of 30 J / g to 80 J / g, 4000 Pa. 16. The method of claim 15, having a complex viscosity of s or less, wherein the complex viscosity is measured at 190 ° C. over an angular frequency range of 0.01 to 100 rad / s.   The method of claim 15 or 16, wherein the polymer blend further comprises one or more particulate solids. (A) a first propylene polymer comprising 90-100% by weight propylene and 0 to less than 10% by weight comonomer and having a Tm of 120 ° C. or higher;
(B) comprising 30 to 90 wt% propylene and 70 to 10 wt% comonomer, having a Mw of 30,000 g / mol or more and having a crystallinity different from the first polymer by at least 5%, A foamed product comprising an in-reactor polymer blend comprising a propylene polymer, wherein the polymer blend is
(I) a Tm of at least 120 ° C;
(Ii) a melt flow rate of 10 dg / min or more;
(Iii) a tensile strength of at least 8 MPa;
(Iv) an elongation at break of at least 200%;
(V) When the extensional viscosity is measured at a strain rate of 1 s ^-1 and 180 ° C, it has a ratio of elongational viscosity at break of 5 or more to linear viscosity and the foamed product has a density of 800 kg / m ³ or less , Foam products.   The foamed product of claim 18 having an average cell size of 1 mm or less.   20. The foamed product according to claim 18 or 19, having 50% or more closed cells.